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2e24ce88 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
a241ec65 | 2 | /* |
29766f1e | 3 | * Read-Copy Update module-based torture test facility |
a241ec65 | 4 | * |
b772e1dd | 5 | * Copyright (C) IBM Corporation, 2005, 2006 |
a241ec65 | 6 | * |
2e24ce88 | 7 | * Authors: Paul E. McKenney <paulmck@linux.ibm.com> |
e0198b29 | 8 | * Josh Triplett <josh@joshtriplett.org> |
a241ec65 PM |
9 | * |
10 | * See also: Documentation/RCU/torture.txt | |
11 | */ | |
60500037 PM |
12 | |
13 | #define pr_fmt(fmt) fmt | |
14 | ||
a241ec65 PM |
15 | #include <linux/types.h> |
16 | #include <linux/kernel.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/kthread.h> | |
20 | #include <linux/err.h> | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/smp.h> | |
9cf8fc6f | 23 | #include <linux/rcupdate_wait.h> |
a241ec65 | 24 | #include <linux/interrupt.h> |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
ae7e81c0 | 26 | #include <uapi/linux/sched/types.h> |
60063497 | 27 | #include <linux/atomic.h> |
a241ec65 | 28 | #include <linux/bitops.h> |
a241ec65 PM |
29 | #include <linux/completion.h> |
30 | #include <linux/moduleparam.h> | |
31 | #include <linux/percpu.h> | |
32 | #include <linux/notifier.h> | |
343e9099 | 33 | #include <linux/reboot.h> |
83144186 | 34 | #include <linux/freezer.h> |
a241ec65 | 35 | #include <linux/cpu.h> |
a241ec65 | 36 | #include <linux/delay.h> |
a241ec65 | 37 | #include <linux/stat.h> |
b2896d2e | 38 | #include <linux/srcu.h> |
1aeb272c | 39 | #include <linux/slab.h> |
52494535 | 40 | #include <linux/trace_clock.h> |
f07767fd | 41 | #include <asm/byteorder.h> |
51b1130e | 42 | #include <linux/torture.h> |
38706bc5 | 43 | #include <linux/vmalloc.h> |
0032f4e8 | 44 | #include <linux/sched/debug.h> |
450efca7 | 45 | #include <linux/sched/sysctl.h> |
e0aff973 | 46 | #include <linux/oom.h> |
d38e6dc6 | 47 | #include <linux/tick.h> |
c1a76c0b | 48 | #include <linux/rcupdate_trace.h> |
a241ec65 | 49 | |
25c36329 PM |
50 | #include "rcu.h" |
51 | ||
a241ec65 | 52 | MODULE_LICENSE("GPL"); |
2e24ce88 | 53 | MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); |
a241ec65 | 54 | |
3b2a4739 PM |
55 | #ifndef data_race |
56 | #define data_race(expr) \ | |
57 | ({ \ | |
58 | expr; \ | |
59 | }) | |
60 | #endif | |
61 | #ifndef ASSERT_EXCLUSIVE_WRITER | |
62 | #define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0) | |
63 | #endif | |
64 | #ifndef ASSERT_EXCLUSIVE_ACCESS | |
65 | #define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0) | |
66 | #endif | |
4102adab | 67 | |
2397d072 PM |
68 | /* Bits for ->extendables field, extendables param, and related definitions. */ |
69 | #define RCUTORTURE_RDR_SHIFT 8 /* Put SRCU index in upper bits. */ | |
70 | #define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1) | |
2ceebc03 PM |
71 | #define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */ |
72 | #define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */ | |
73 | #define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */ | |
74 | #define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */ | |
75 | #define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */ | |
76 | #define RCUTORTURE_RDR_RCU 0x20 /* ... entering another RCU reader. */ | |
77 | #define RCUTORTURE_RDR_NBITS 6 /* Number of bits defined above. */ | |
78 | #define RCUTORTURE_MAX_EXTEND \ | |
79 | (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ | |
80 | RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) | |
2397d072 PM |
81 | #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ |
82 | /* Must be power of two minus one. */ | |
c116dba6 | 83 | #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) |
2397d072 | 84 | |
2397d072 PM |
85 | torture_param(int, extendables, RCUTORTURE_MAX_EXTEND, |
86 | "Extend readers by disabling bh (1), irqs (2), or preempt (4)"); | |
9e250225 PM |
87 | torture_param(int, fqs_duration, 0, |
88 | "Duration of fqs bursts (us), 0 to disable"); | |
89 | torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); | |
90 | torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); | |
1b27291b PM |
91 | torture_param(bool, fwd_progress, 1, "Test grace-period forward progress"); |
92 | torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait"); | |
93 | torture_param(int, fwd_progress_holdoff, 60, | |
94 | "Time between forward-progress tests (s)"); | |
95 | torture_param(bool, fwd_progress_need_resched, 1, | |
96 | "Hide cond_resched() behind need_resched()"); | |
a48f3fad | 97 | torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); |
9e250225 PM |
98 | torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); |
99 | torture_param(bool, gp_normal, false, | |
100 | "Use normal (non-expedited) GP wait primitives"); | |
f0bf8fab | 101 | torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); |
9e250225 PM |
102 | torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); |
103 | torture_param(int, n_barrier_cbs, 0, | |
104 | "# of callbacks/kthreads for barrier testing"); | |
105 | torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); | |
106 | torture_param(int, nreaders, -1, "Number of RCU reader threads"); | |
107 | torture_param(int, object_debug, 0, | |
108 | "Enable debug-object double call_rcu() testing"); | |
109 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); | |
110 | torture_param(int, onoff_interval, 0, | |
028be12b | 111 | "Time between CPU hotplugs (jiffies), 0=disable"); |
9e250225 PM |
112 | torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); |
113 | torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); | |
114 | torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); | |
115 | torture_param(int, stall_cpu_holdoff, 10, | |
116 | "Time to wait before starting stall (s)."); | |
2b1516e5 | 117 | torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); |
19a8ff95 | 118 | torture_param(int, stall_cpu_block, 0, "Sleep while stalling."); |
55b2dcf5 PM |
119 | torture_param(int, stall_gp_kthread, 0, |
120 | "Grace-period kthread stall duration (s)."); | |
9e250225 PM |
121 | torture_param(int, stat_interval, 60, |
122 | "Number of seconds between stats printk()s"); | |
123 | torture_param(int, stutter, 5, "Number of seconds to run/halt test"); | |
124 | torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); | |
125 | torture_param(int, test_boost_duration, 4, | |
126 | "Duration of each boost test, seconds."); | |
127 | torture_param(int, test_boost_interval, 7, | |
128 | "Interval between boost tests, seconds."); | |
129 | torture_param(bool, test_no_idle_hz, true, | |
130 | "Test support for tickless idle CPUs"); | |
90127d60 | 131 | torture_param(int, verbose, 1, |
b5daa8f3 | 132 | "Enable verbose debugging printk()s"); |
9e250225 | 133 | |
d10453e9 | 134 | static char *torture_type = "rcu"; |
d6ad6711 | 135 | module_param(torture_type, charp, 0444); |
c770c82a | 136 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); |
a241ec65 | 137 | |
a241ec65 PM |
138 | static int nrealreaders; |
139 | static struct task_struct *writer_task; | |
b772e1dd | 140 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
141 | static struct task_struct **reader_tasks; |
142 | static struct task_struct *stats_task; | |
bf66f18e | 143 | static struct task_struct *fqs_task; |
8e8be45e | 144 | static struct task_struct *boost_tasks[NR_CPUS]; |
c13f3757 | 145 | static struct task_struct *stall_task; |
1b27291b | 146 | static struct task_struct *fwd_prog_task; |
fae4b54f PM |
147 | static struct task_struct **barrier_cbs_tasks; |
148 | static struct task_struct *barrier_task; | |
a241ec65 PM |
149 | |
150 | #define RCU_TORTURE_PIPE_LEN 10 | |
151 | ||
152 | struct rcu_torture { | |
153 | struct rcu_head rtort_rcu; | |
154 | int rtort_pipe_count; | |
155 | struct list_head rtort_free; | |
996417d2 | 156 | int rtort_mbtest; |
a241ec65 PM |
157 | }; |
158 | ||
a241ec65 | 159 | static LIST_HEAD(rcu_torture_freelist); |
0ddea0ea | 160 | static struct rcu_torture __rcu *rcu_torture_current; |
4a298656 | 161 | static unsigned long rcu_torture_current_version; |
a241ec65 PM |
162 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
163 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
67522bee PM |
164 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); |
165 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); | |
a241ec65 | 166 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; |
b2896d2e PM |
167 | static atomic_t n_rcu_torture_alloc; |
168 | static atomic_t n_rcu_torture_alloc_fail; | |
169 | static atomic_t n_rcu_torture_free; | |
170 | static atomic_t n_rcu_torture_mberror; | |
171 | static atomic_t n_rcu_torture_error; | |
fae4b54f | 172 | static long n_rcu_torture_barrier_error; |
8e8be45e PM |
173 | static long n_rcu_torture_boost_ktrerror; |
174 | static long n_rcu_torture_boost_rterror; | |
8e8be45e PM |
175 | static long n_rcu_torture_boost_failure; |
176 | static long n_rcu_torture_boosts; | |
8da9a595 | 177 | static atomic_long_t n_rcu_torture_timers; |
fae4b54f | 178 | static long n_barrier_attempts; |
bf5b6435 | 179 | static long n_barrier_successes; /* did rcu_barrier test succeed? */ |
e3033736 | 180 | static struct list_head rcu_torture_removed; |
60013d5d | 181 | static unsigned long shutdown_jiffies; |
d120f65f | 182 | |
ad0dc7f9 PM |
183 | static int rcu_torture_writer_state; |
184 | #define RTWS_FIXED_DELAY 0 | |
185 | #define RTWS_DELAY 1 | |
186 | #define RTWS_REPLACE 2 | |
187 | #define RTWS_DEF_FREE 3 | |
188 | #define RTWS_EXP_SYNC 4 | |
a48f3fad PM |
189 | #define RTWS_COND_GET 5 |
190 | #define RTWS_COND_SYNC 6 | |
f0bf8fab PM |
191 | #define RTWS_SYNC 7 |
192 | #define RTWS_STUTTER 8 | |
193 | #define RTWS_STOPPING 9 | |
18aff33e PM |
194 | static const char * const rcu_torture_writer_state_names[] = { |
195 | "RTWS_FIXED_DELAY", | |
196 | "RTWS_DELAY", | |
197 | "RTWS_REPLACE", | |
198 | "RTWS_DEF_FREE", | |
199 | "RTWS_EXP_SYNC", | |
200 | "RTWS_COND_GET", | |
201 | "RTWS_COND_SYNC", | |
202 | "RTWS_SYNC", | |
203 | "RTWS_STUTTER", | |
204 | "RTWS_STOPPING", | |
205 | }; | |
206 | ||
c116dba6 PM |
207 | /* Record reader segment types and duration for first failing read. */ |
208 | struct rt_read_seg { | |
209 | int rt_readstate; | |
210 | unsigned long rt_delay_jiffies; | |
211 | unsigned long rt_delay_ms; | |
212 | unsigned long rt_delay_us; | |
213 | bool rt_preempted; | |
214 | }; | |
215 | static int err_segs_recorded; | |
216 | static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; | |
217 | static int rt_read_nsegs; | |
218 | ||
18aff33e PM |
219 | static const char *rcu_torture_writer_state_getname(void) |
220 | { | |
221 | unsigned int i = READ_ONCE(rcu_torture_writer_state); | |
222 | ||
223 | if (i >= ARRAY_SIZE(rcu_torture_writer_state_names)) | |
224 | return "???"; | |
225 | return rcu_torture_writer_state_names[i]; | |
226 | } | |
ad0dc7f9 | 227 | |
3acf4a9a | 228 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) |
8e8be45e | 229 | #define rcu_can_boost() 1 |
3acf4a9a | 230 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 231 | #define rcu_can_boost() 0 |
3acf4a9a | 232 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 233 | |
e4aa0da3 SR |
234 | #ifdef CONFIG_RCU_TRACE |
235 | static u64 notrace rcu_trace_clock_local(void) | |
236 | { | |
237 | u64 ts = trace_clock_local(); | |
a3b7b6c2 PM |
238 | |
239 | (void)do_div(ts, NSEC_PER_USEC); | |
e4aa0da3 SR |
240 | return ts; |
241 | } | |
242 | #else /* #ifdef CONFIG_RCU_TRACE */ | |
243 | static u64 notrace rcu_trace_clock_local(void) | |
244 | { | |
245 | return 0ULL; | |
246 | } | |
247 | #endif /* #else #ifdef CONFIG_RCU_TRACE */ | |
248 | ||
60013d5d PM |
249 | /* |
250 | * Stop aggressive CPU-hog tests a bit before the end of the test in order | |
251 | * to avoid interfering with test shutdown. | |
252 | */ | |
253 | static bool shutdown_time_arrived(void) | |
254 | { | |
255 | return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ); | |
256 | } | |
257 | ||
8e8be45e | 258 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
58ade2db | 259 | static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ |
8e8be45e | 260 | /* and boost task create/destroy. */ |
fae4b54f | 261 | static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ |
c6ebcbb6 | 262 | static bool barrier_phase; /* Test phase. */ |
fae4b54f PM |
263 | static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ |
264 | static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ | |
265 | static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); | |
8e8be45e | 266 | |
48718485 PM |
267 | static bool rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */ |
268 | ||
a241ec65 PM |
269 | /* |
270 | * Allocate an element from the rcu_tortures pool. | |
271 | */ | |
97a41e26 | 272 | static struct rcu_torture * |
a241ec65 PM |
273 | rcu_torture_alloc(void) |
274 | { | |
275 | struct list_head *p; | |
276 | ||
adac1665 | 277 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
278 | if (list_empty(&rcu_torture_freelist)) { |
279 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 280 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
281 | return NULL; |
282 | } | |
283 | atomic_inc(&n_rcu_torture_alloc); | |
284 | p = rcu_torture_freelist.next; | |
285 | list_del_init(p); | |
adac1665 | 286 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
287 | return container_of(p, struct rcu_torture, rtort_free); |
288 | } | |
289 | ||
290 | /* | |
291 | * Free an element to the rcu_tortures pool. | |
292 | */ | |
293 | static void | |
294 | rcu_torture_free(struct rcu_torture *p) | |
295 | { | |
296 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 297 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 298 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 299 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
300 | } |
301 | ||
72e9bb54 PM |
302 | /* |
303 | * Operations vector for selecting different types of tests. | |
304 | */ | |
305 | ||
306 | struct rcu_torture_ops { | |
ad0dc7f9 | 307 | int ttype; |
72e9bb54 | 308 | void (*init)(void); |
ca1d51ed | 309 | void (*cleanup)(void); |
72e9bb54 | 310 | int (*readlock)(void); |
c116dba6 PM |
311 | void (*read_delay)(struct torture_random_state *rrsp, |
312 | struct rt_read_seg *rtrsp); | |
72e9bb54 | 313 | void (*readunlock)(int idx); |
17ef2fe9 | 314 | unsigned long (*get_gp_seq)(void); |
d7219312 | 315 | unsigned long (*gp_diff)(unsigned long new, unsigned long old); |
0acc512c | 316 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 317 | void (*sync)(void); |
2ec1f2d9 | 318 | void (*exp_sync)(void); |
a48f3fad PM |
319 | unsigned long (*get_state)(void); |
320 | void (*cond_sync)(unsigned long oldstate); | |
db3e8db4 | 321 | call_rcu_func_t call; |
2326974d | 322 | void (*cb_barrier)(void); |
bf66f18e | 323 | void (*fqs)(void); |
eea203fe | 324 | void (*stats)(void); |
1b27291b | 325 | int (*stall_dur)(void); |
0acc512c | 326 | int irq_capable; |
8e8be45e | 327 | int can_boost; |
2397d072 | 328 | int extendables; |
5eabea59 | 329 | int slow_gps; |
e66c33d5 | 330 | const char *name; |
72e9bb54 | 331 | }; |
a71fca58 PM |
332 | |
333 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
334 | |
335 | /* | |
336 | * Definitions for rcu torture testing. | |
337 | */ | |
338 | ||
a49a4af7 | 339 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
340 | { |
341 | rcu_read_lock(); | |
342 | return 0; | |
343 | } | |
344 | ||
c116dba6 PM |
345 | static void |
346 | rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) | |
b2896d2e | 347 | { |
d0af39e8 PM |
348 | unsigned long started; |
349 | unsigned long completed; | |
b8d57a76 | 350 | const unsigned long shortdelay_us = 200; |
1e696765 | 351 | unsigned long longdelay_ms = 300; |
d0af39e8 | 352 | unsigned long long ts; |
b2896d2e | 353 | |
b8d57a76 JT |
354 | /* We want a short delay sometimes to make a reader delay the grace |
355 | * period, and we want a long delay occasionally to trigger | |
356 | * force_quiescent_state. */ | |
b2896d2e | 357 | |
102c14d2 | 358 | if (!READ_ONCE(rcu_fwd_cb_nodelay) && |
48718485 | 359 | !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { |
17ef2fe9 | 360 | started = cur_ops->get_gp_seq(); |
d0af39e8 | 361 | ts = rcu_trace_clock_local(); |
1e696765 PM |
362 | if (preempt_count() & (SOFTIRQ_MASK | HARDIRQ_MASK)) |
363 | longdelay_ms = 5; /* Avoid triggering BH limits. */ | |
b8d57a76 | 364 | mdelay(longdelay_ms); |
c116dba6 | 365 | rtrsp->rt_delay_ms = longdelay_ms; |
17ef2fe9 | 366 | completed = cur_ops->get_gp_seq(); |
d0af39e8 PM |
367 | do_trace_rcu_torture_read(cur_ops->name, NULL, ts, |
368 | started, completed); | |
369 | } | |
c116dba6 | 370 | if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { |
b8d57a76 | 371 | udelay(shortdelay_us); |
c116dba6 PM |
372 | rtrsp->rt_delay_us = shortdelay_us; |
373 | } | |
51b1130e | 374 | if (!preempt_count() && |
c116dba6 | 375 | !(torture_random(rrsp) % (nrealreaders * 500))) { |
cc1321c9 | 376 | torture_preempt_schedule(); /* QS only if preemptible. */ |
c116dba6 PM |
377 | rtrsp->rt_preempted = true; |
378 | } | |
b2896d2e PM |
379 | } |
380 | ||
a49a4af7 | 381 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
382 | { |
383 | rcu_read_unlock(); | |
384 | } | |
385 | ||
a48f3fad PM |
386 | /* |
387 | * Update callback in the pipe. This should be invoked after a grace period. | |
388 | */ | |
389 | static bool | |
390 | rcu_torture_pipe_update_one(struct rcu_torture *rp) | |
391 | { | |
392 | int i; | |
393 | ||
20248910 | 394 | i = READ_ONCE(rp->rtort_pipe_count); |
a48f3fad PM |
395 | if (i > RCU_TORTURE_PIPE_LEN) |
396 | i = RCU_TORTURE_PIPE_LEN; | |
397 | atomic_inc(&rcu_torture_wcount[i]); | |
20248910 PM |
398 | WRITE_ONCE(rp->rtort_pipe_count, i + 1); |
399 | if (rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
a48f3fad PM |
400 | rp->rtort_mbtest = 0; |
401 | return true; | |
402 | } | |
403 | return false; | |
404 | } | |
405 | ||
406 | /* | |
407 | * Update all callbacks in the pipe. Suitable for synchronous grace-period | |
408 | * primitives. | |
409 | */ | |
410 | static void | |
411 | rcu_torture_pipe_update(struct rcu_torture *old_rp) | |
412 | { | |
413 | struct rcu_torture *rp; | |
414 | struct rcu_torture *rp1; | |
415 | ||
416 | if (old_rp) | |
417 | list_add(&old_rp->rtort_free, &rcu_torture_removed); | |
418 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
419 | if (rcu_torture_pipe_update_one(rp)) { | |
420 | list_del(&rp->rtort_free); | |
421 | rcu_torture_free(rp); | |
422 | } | |
423 | } | |
424 | } | |
425 | ||
72e9bb54 PM |
426 | static void |
427 | rcu_torture_cb(struct rcu_head *p) | |
428 | { | |
72e9bb54 PM |
429 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); |
430 | ||
36970bb9 | 431 | if (torture_must_stop_irq()) { |
72e9bb54 PM |
432 | /* Test is ending, just drop callbacks on the floor. */ |
433 | /* The next initialization will pick up the pieces. */ | |
434 | return; | |
435 | } | |
a48f3fad | 436 | if (rcu_torture_pipe_update_one(rp)) |
72e9bb54 | 437 | rcu_torture_free(rp); |
a48f3fad | 438 | else |
0acc512c | 439 | cur_ops->deferred_free(rp); |
72e9bb54 PM |
440 | } |
441 | ||
6b80da42 | 442 | static unsigned long rcu_no_completed(void) |
d9a3da06 PM |
443 | { |
444 | return 0; | |
445 | } | |
446 | ||
72e9bb54 PM |
447 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
448 | { | |
449 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
450 | } | |
451 | ||
e3033736 JT |
452 | static void rcu_sync_torture_init(void) |
453 | { | |
454 | INIT_LIST_HEAD(&rcu_torture_removed); | |
455 | } | |
456 | ||
2ec1f2d9 | 457 | static struct rcu_torture_ops rcu_ops = { |
ad0dc7f9 | 458 | .ttype = RCU_FLAVOR, |
0acc512c | 459 | .init = rcu_sync_torture_init, |
0acc512c PM |
460 | .readlock = rcu_torture_read_lock, |
461 | .read_delay = rcu_read_delay, | |
462 | .readunlock = rcu_torture_read_unlock, | |
17ef2fe9 | 463 | .get_gp_seq = rcu_get_gp_seq, |
d7219312 | 464 | .gp_diff = rcu_seq_diff, |
2ec1f2d9 | 465 | .deferred_free = rcu_torture_deferred_free, |
0acc512c | 466 | .sync = synchronize_rcu, |
2ec1f2d9 | 467 | .exp_sync = synchronize_rcu_expedited, |
a48f3fad PM |
468 | .get_state = get_state_synchronize_rcu, |
469 | .cond_sync = cond_synchronize_rcu, | |
2ec1f2d9 PM |
470 | .call = call_rcu, |
471 | .cb_barrier = rcu_barrier, | |
bf66f18e | 472 | .fqs = rcu_force_quiescent_state, |
d9a3da06 | 473 | .stats = NULL, |
1b27291b | 474 | .stall_dur = rcu_jiffies_till_stall_check, |
d9a3da06 | 475 | .irq_capable = 1, |
8e8be45e | 476 | .can_boost = rcu_can_boost(), |
c0335743 | 477 | .extendables = RCUTORTURE_MAX_EXTEND, |
2ec1f2d9 | 478 | .name = "rcu" |
d9a3da06 PM |
479 | }; |
480 | ||
ff20e251 PM |
481 | /* |
482 | * Don't even think about trying any of these in real life!!! | |
483 | * The names includes "busted", and they really means it! | |
484 | * The only purpose of these functions is to provide a buggy RCU | |
485 | * implementation to make sure that rcutorture correctly emits | |
486 | * buggy-RCU error messages. | |
487 | */ | |
488 | static void rcu_busted_torture_deferred_free(struct rcu_torture *p) | |
489 | { | |
490 | /* This is a deliberate bug for testing purposes only! */ | |
491 | rcu_torture_cb(&p->rtort_rcu); | |
492 | } | |
493 | ||
494 | static void synchronize_rcu_busted(void) | |
495 | { | |
496 | /* This is a deliberate bug for testing purposes only! */ | |
497 | } | |
498 | ||
499 | static void | |
b6a4ae76 | 500 | call_rcu_busted(struct rcu_head *head, rcu_callback_t func) |
ff20e251 PM |
501 | { |
502 | /* This is a deliberate bug for testing purposes only! */ | |
503 | func(head); | |
504 | } | |
505 | ||
506 | static struct rcu_torture_ops rcu_busted_ops = { | |
ad0dc7f9 | 507 | .ttype = INVALID_RCU_FLAVOR, |
ff20e251 PM |
508 | .init = rcu_sync_torture_init, |
509 | .readlock = rcu_torture_read_lock, | |
510 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
511 | .readunlock = rcu_torture_read_unlock, | |
17ef2fe9 | 512 | .get_gp_seq = rcu_no_completed, |
ff20e251 PM |
513 | .deferred_free = rcu_busted_torture_deferred_free, |
514 | .sync = synchronize_rcu_busted, | |
515 | .exp_sync = synchronize_rcu_busted, | |
516 | .call = call_rcu_busted, | |
517 | .cb_barrier = NULL, | |
518 | .fqs = NULL, | |
519 | .stats = NULL, | |
520 | .irq_capable = 1, | |
b3c98314 | 521 | .name = "busted" |
ff20e251 PM |
522 | }; |
523 | ||
b2896d2e PM |
524 | /* |
525 | * Definitions for srcu torture testing. | |
526 | */ | |
527 | ||
cda4dc81 | 528 | DEFINE_STATIC_SRCU(srcu_ctl); |
ca1d51ed PM |
529 | static struct srcu_struct srcu_ctld; |
530 | static struct srcu_struct *srcu_ctlp = &srcu_ctl; | |
b2896d2e | 531 | |
ca1d51ed | 532 | static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) |
b2896d2e | 533 | { |
ca1d51ed | 534 | return srcu_read_lock(srcu_ctlp); |
b2896d2e PM |
535 | } |
536 | ||
c116dba6 PM |
537 | static void |
538 | srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) | |
b2896d2e PM |
539 | { |
540 | long delay; | |
541 | const long uspertick = 1000000 / HZ; | |
542 | const long longdelay = 10; | |
543 | ||
544 | /* We want there to be long-running readers, but not all the time. */ | |
545 | ||
51b1130e PM |
546 | delay = torture_random(rrsp) % |
547 | (nrealreaders * 2 * longdelay * uspertick); | |
c116dba6 | 548 | if (!delay && in_task()) { |
b2896d2e | 549 | schedule_timeout_interruptible(longdelay); |
c116dba6 PM |
550 | rtrsp->rt_delay_jiffies = longdelay; |
551 | } else { | |
552 | rcu_read_delay(rrsp, rtrsp); | |
553 | } | |
b2896d2e PM |
554 | } |
555 | ||
ca1d51ed | 556 | static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) |
b2896d2e | 557 | { |
ca1d51ed | 558 | srcu_read_unlock(srcu_ctlp, idx); |
b2896d2e PM |
559 | } |
560 | ||
6b80da42 | 561 | static unsigned long srcu_torture_completed(void) |
b2896d2e | 562 | { |
ca1d51ed | 563 | return srcu_batches_completed(srcu_ctlp); |
b2896d2e PM |
564 | } |
565 | ||
9059c940 LJ |
566 | static void srcu_torture_deferred_free(struct rcu_torture *rp) |
567 | { | |
ca1d51ed | 568 | call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); |
9059c940 LJ |
569 | } |
570 | ||
b772e1dd JT |
571 | static void srcu_torture_synchronize(void) |
572 | { | |
ca1d51ed | 573 | synchronize_srcu(srcu_ctlp); |
b772e1dd JT |
574 | } |
575 | ||
e3f8d378 | 576 | static void srcu_torture_call(struct rcu_head *head, |
b6a4ae76 | 577 | rcu_callback_t func) |
e3f8d378 | 578 | { |
ca1d51ed | 579 | call_srcu(srcu_ctlp, head, func); |
e3f8d378 PM |
580 | } |
581 | ||
582 | static void srcu_torture_barrier(void) | |
583 | { | |
ca1d51ed | 584 | srcu_barrier(srcu_ctlp); |
e3f8d378 PM |
585 | } |
586 | ||
eea203fe | 587 | static void srcu_torture_stats(void) |
b2896d2e | 588 | { |
115a1a52 | 589 | srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); |
b2896d2e PM |
590 | } |
591 | ||
2ec1f2d9 PM |
592 | static void srcu_torture_synchronize_expedited(void) |
593 | { | |
ca1d51ed | 594 | synchronize_srcu_expedited(srcu_ctlp); |
2ec1f2d9 PM |
595 | } |
596 | ||
b2896d2e | 597 | static struct rcu_torture_ops srcu_ops = { |
ad0dc7f9 | 598 | .ttype = SRCU_FLAVOR, |
cda4dc81 | 599 | .init = rcu_sync_torture_init, |
0acc512c PM |
600 | .readlock = srcu_torture_read_lock, |
601 | .read_delay = srcu_read_delay, | |
602 | .readunlock = srcu_torture_read_unlock, | |
17ef2fe9 | 603 | .get_gp_seq = srcu_torture_completed, |
9059c940 | 604 | .deferred_free = srcu_torture_deferred_free, |
0acc512c | 605 | .sync = srcu_torture_synchronize, |
2ec1f2d9 | 606 | .exp_sync = srcu_torture_synchronize_expedited, |
e3f8d378 PM |
607 | .call = srcu_torture_call, |
608 | .cb_barrier = srcu_torture_barrier, | |
0acc512c | 609 | .stats = srcu_torture_stats, |
5e741fa9 | 610 | .irq_capable = 1, |
0acc512c | 611 | .name = "srcu" |
b2896d2e PM |
612 | }; |
613 | ||
ca1d51ed PM |
614 | static void srcu_torture_init(void) |
615 | { | |
616 | rcu_sync_torture_init(); | |
617 | WARN_ON(init_srcu_struct(&srcu_ctld)); | |
618 | srcu_ctlp = &srcu_ctld; | |
619 | } | |
620 | ||
621 | static void srcu_torture_cleanup(void) | |
622 | { | |
f5ad3991 | 623 | cleanup_srcu_struct(&srcu_ctld); |
ca1d51ed PM |
624 | srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ |
625 | } | |
626 | ||
627 | /* As above, but dynamically allocated. */ | |
628 | static struct rcu_torture_ops srcud_ops = { | |
629 | .ttype = SRCU_FLAVOR, | |
630 | .init = srcu_torture_init, | |
631 | .cleanup = srcu_torture_cleanup, | |
632 | .readlock = srcu_torture_read_lock, | |
633 | .read_delay = srcu_read_delay, | |
634 | .readunlock = srcu_torture_read_unlock, | |
17ef2fe9 | 635 | .get_gp_seq = srcu_torture_completed, |
ca1d51ed PM |
636 | .deferred_free = srcu_torture_deferred_free, |
637 | .sync = srcu_torture_synchronize, | |
638 | .exp_sync = srcu_torture_synchronize_expedited, | |
639 | .call = srcu_torture_call, | |
640 | .cb_barrier = srcu_torture_barrier, | |
641 | .stats = srcu_torture_stats, | |
5e741fa9 | 642 | .irq_capable = 1, |
ca1d51ed PM |
643 | .name = "srcud" |
644 | }; | |
645 | ||
2397d072 PM |
646 | /* As above, but broken due to inappropriate reader extension. */ |
647 | static struct rcu_torture_ops busted_srcud_ops = { | |
648 | .ttype = SRCU_FLAVOR, | |
649 | .init = srcu_torture_init, | |
650 | .cleanup = srcu_torture_cleanup, | |
651 | .readlock = srcu_torture_read_lock, | |
652 | .read_delay = rcu_read_delay, | |
653 | .readunlock = srcu_torture_read_unlock, | |
654 | .get_gp_seq = srcu_torture_completed, | |
655 | .deferred_free = srcu_torture_deferred_free, | |
656 | .sync = srcu_torture_synchronize, | |
657 | .exp_sync = srcu_torture_synchronize_expedited, | |
658 | .call = srcu_torture_call, | |
659 | .cb_barrier = srcu_torture_barrier, | |
660 | .stats = srcu_torture_stats, | |
661 | .irq_capable = 1, | |
662 | .extendables = RCUTORTURE_MAX_EXTEND, | |
663 | .name = "busted_srcud" | |
664 | }; | |
665 | ||
69c60455 PM |
666 | /* |
667 | * Definitions for RCU-tasks torture testing. | |
668 | */ | |
669 | ||
670 | static int tasks_torture_read_lock(void) | |
671 | { | |
672 | return 0; | |
673 | } | |
674 | ||
675 | static void tasks_torture_read_unlock(int idx) | |
676 | { | |
677 | } | |
678 | ||
679 | static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) | |
680 | { | |
681 | call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); | |
682 | } | |
683 | ||
9cf8fc6f PM |
684 | static void synchronize_rcu_mult_test(void) |
685 | { | |
686 | synchronize_rcu_mult(call_rcu_tasks, call_rcu); | |
687 | } | |
688 | ||
69c60455 PM |
689 | static struct rcu_torture_ops tasks_ops = { |
690 | .ttype = RCU_TASKS_FLAVOR, | |
691 | .init = rcu_sync_torture_init, | |
692 | .readlock = tasks_torture_read_lock, | |
693 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
694 | .readunlock = tasks_torture_read_unlock, | |
17ef2fe9 | 695 | .get_gp_seq = rcu_no_completed, |
69c60455 PM |
696 | .deferred_free = rcu_tasks_torture_deferred_free, |
697 | .sync = synchronize_rcu_tasks, | |
9cf8fc6f | 698 | .exp_sync = synchronize_rcu_mult_test, |
69c60455 PM |
699 | .call = call_rcu_tasks, |
700 | .cb_barrier = rcu_barrier_tasks, | |
701 | .fqs = NULL, | |
702 | .stats = NULL, | |
703 | .irq_capable = 1, | |
5eabea59 | 704 | .slow_gps = 1, |
69c60455 PM |
705 | .name = "tasks" |
706 | }; | |
707 | ||
c682db55 PM |
708 | /* |
709 | * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. | |
710 | * This implementation does not necessarily work well with CPU hotplug. | |
711 | */ | |
712 | ||
713 | static void synchronize_rcu_trivial(void) | |
714 | { | |
715 | int cpu; | |
716 | ||
717 | for_each_online_cpu(cpu) { | |
718 | rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu)); | |
719 | WARN_ON_ONCE(raw_smp_processor_id() != cpu); | |
720 | } | |
721 | } | |
722 | ||
723 | static int rcu_torture_read_lock_trivial(void) __acquires(RCU) | |
724 | { | |
725 | preempt_disable(); | |
726 | return 0; | |
727 | } | |
728 | ||
729 | static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU) | |
730 | { | |
731 | preempt_enable(); | |
732 | } | |
733 | ||
734 | static struct rcu_torture_ops trivial_ops = { | |
735 | .ttype = RCU_TRIVIAL_FLAVOR, | |
736 | .init = rcu_sync_torture_init, | |
737 | .readlock = rcu_torture_read_lock_trivial, | |
738 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
739 | .readunlock = rcu_torture_read_unlock_trivial, | |
740 | .get_gp_seq = rcu_no_completed, | |
741 | .sync = synchronize_rcu_trivial, | |
742 | .exp_sync = synchronize_rcu_trivial, | |
743 | .fqs = NULL, | |
744 | .stats = NULL, | |
745 | .irq_capable = 1, | |
746 | .name = "trivial" | |
747 | }; | |
748 | ||
3d6e43c7 PM |
749 | /* |
750 | * Definitions for rude RCU-tasks torture testing. | |
751 | */ | |
752 | ||
753 | static void rcu_tasks_rude_torture_deferred_free(struct rcu_torture *p) | |
754 | { | |
755 | call_rcu_tasks_rude(&p->rtort_rcu, rcu_torture_cb); | |
756 | } | |
757 | ||
758 | static struct rcu_torture_ops tasks_rude_ops = { | |
759 | .ttype = RCU_TASKS_RUDE_FLAVOR, | |
760 | .init = rcu_sync_torture_init, | |
761 | .readlock = rcu_torture_read_lock_trivial, | |
762 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
763 | .readunlock = rcu_torture_read_unlock_trivial, | |
764 | .get_gp_seq = rcu_no_completed, | |
765 | .deferred_free = rcu_tasks_rude_torture_deferred_free, | |
766 | .sync = synchronize_rcu_tasks_rude, | |
767 | .exp_sync = synchronize_rcu_tasks_rude, | |
768 | .call = call_rcu_tasks_rude, | |
769 | .cb_barrier = rcu_barrier_tasks_rude, | |
770 | .fqs = NULL, | |
771 | .stats = NULL, | |
772 | .irq_capable = 1, | |
773 | .name = "tasks-rude" | |
774 | }; | |
775 | ||
c1a76c0b PM |
776 | /* |
777 | * Definitions for tracing RCU-tasks torture testing. | |
778 | */ | |
779 | ||
780 | static int tasks_tracing_torture_read_lock(void) | |
781 | { | |
782 | rcu_read_lock_trace(); | |
783 | return 0; | |
784 | } | |
785 | ||
786 | static void tasks_tracing_torture_read_unlock(int idx) | |
787 | { | |
788 | rcu_read_unlock_trace(); | |
789 | } | |
790 | ||
791 | static void rcu_tasks_tracing_torture_deferred_free(struct rcu_torture *p) | |
792 | { | |
793 | call_rcu_tasks_trace(&p->rtort_rcu, rcu_torture_cb); | |
794 | } | |
795 | ||
796 | static struct rcu_torture_ops tasks_tracing_ops = { | |
797 | .ttype = RCU_TASKS_TRACING_FLAVOR, | |
798 | .init = rcu_sync_torture_init, | |
799 | .readlock = tasks_tracing_torture_read_lock, | |
800 | .read_delay = srcu_read_delay, /* just reuse srcu's version. */ | |
801 | .readunlock = tasks_tracing_torture_read_unlock, | |
802 | .get_gp_seq = rcu_no_completed, | |
803 | .deferred_free = rcu_tasks_tracing_torture_deferred_free, | |
804 | .sync = synchronize_rcu_tasks_trace, | |
805 | .exp_sync = synchronize_rcu_tasks_trace, | |
806 | .call = call_rcu_tasks_trace, | |
807 | .cb_barrier = rcu_barrier_tasks_trace, | |
808 | .fqs = NULL, | |
809 | .stats = NULL, | |
810 | .irq_capable = 1, | |
811 | .slow_gps = 1, | |
812 | .name = "tasks-tracing" | |
813 | }; | |
814 | ||
d7219312 PM |
815 | static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) |
816 | { | |
817 | if (!cur_ops->gp_diff) | |
818 | return new - old; | |
819 | return cur_ops->gp_diff(new, old); | |
820 | } | |
821 | ||
5be5d1a1 PM |
822 | static bool __maybe_unused torturing_tasks(void) |
823 | { | |
3d6e43c7 | 824 | return cur_ops == &tasks_ops || cur_ops == &tasks_rude_ops; |
5be5d1a1 PM |
825 | } |
826 | ||
8e8be45e PM |
827 | /* |
828 | * RCU torture priority-boost testing. Runs one real-time thread per | |
829 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
830 | * spinning waiting for them to be invoked. If a given callback takes | |
831 | * too long to be invoked, we assume that priority inversion has occurred. | |
832 | */ | |
833 | ||
834 | struct rcu_boost_inflight { | |
835 | struct rcu_head rcu; | |
836 | int inflight; | |
837 | }; | |
838 | ||
839 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
840 | { | |
841 | struct rcu_boost_inflight *rbip = | |
842 | container_of(head, struct rcu_boost_inflight, rcu); | |
843 | ||
6c7ed42c PM |
844 | /* Ensure RCU-core accesses precede clearing ->inflight */ |
845 | smp_store_release(&rbip->inflight, 0); | |
8e8be45e PM |
846 | } |
847 | ||
450efca7 JFG |
848 | static int old_rt_runtime = -1; |
849 | ||
850 | static void rcu_torture_disable_rt_throttle(void) | |
851 | { | |
852 | /* | |
853 | * Disable RT throttling so that rcutorture's boost threads don't get | |
854 | * throttled. Only possible if rcutorture is built-in otherwise the | |
855 | * user should manually do this by setting the sched_rt_period_us and | |
856 | * sched_rt_runtime sysctls. | |
857 | */ | |
858 | if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) | |
859 | return; | |
860 | ||
861 | old_rt_runtime = sysctl_sched_rt_runtime; | |
862 | sysctl_sched_rt_runtime = -1; | |
863 | } | |
864 | ||
865 | static void rcu_torture_enable_rt_throttle(void) | |
866 | { | |
867 | if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) | |
868 | return; | |
869 | ||
870 | sysctl_sched_rt_runtime = old_rt_runtime; | |
871 | old_rt_runtime = -1; | |
872 | } | |
873 | ||
3b745c89 JFG |
874 | static bool rcu_torture_boost_failed(unsigned long start, unsigned long end) |
875 | { | |
876 | if (end - start > test_boost_duration * HZ - HZ / 2) { | |
877 | VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); | |
878 | n_rcu_torture_boost_failure++; | |
879 | ||
880 | return true; /* failed */ | |
881 | } | |
882 | ||
883 | return false; /* passed */ | |
884 | } | |
885 | ||
8e8be45e PM |
886 | static int rcu_torture_boost(void *arg) |
887 | { | |
888 | unsigned long call_rcu_time; | |
889 | unsigned long endtime; | |
890 | unsigned long oldstarttime; | |
891 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
892 | struct sched_param sp; | |
893 | ||
5ccf60f2 | 894 | VERBOSE_TOROUT_STRING("rcu_torture_boost started"); |
8e8be45e PM |
895 | |
896 | /* Set real-time priority. */ | |
897 | sp.sched_priority = 1; | |
898 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
5ccf60f2 | 899 | VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); |
8e8be45e PM |
900 | n_rcu_torture_boost_rterror++; |
901 | } | |
902 | ||
561190e3 | 903 | init_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
904 | /* Each pass through the following loop does one boost-test cycle. */ |
905 | do { | |
3b745c89 JFG |
906 | /* Track if the test failed already in this test interval? */ |
907 | bool failed = false; | |
908 | ||
909 | /* Increment n_rcu_torture_boosts once per boost-test */ | |
910 | while (!kthread_should_stop()) { | |
911 | if (mutex_trylock(&boost_mutex)) { | |
912 | n_rcu_torture_boosts++; | |
913 | mutex_unlock(&boost_mutex); | |
914 | break; | |
915 | } | |
916 | schedule_timeout_uninterruptible(1); | |
917 | } | |
918 | if (kthread_should_stop()) | |
919 | goto checkwait; | |
920 | ||
8e8be45e PM |
921 | /* Wait for the next test interval. */ |
922 | oldstarttime = boost_starttime; | |
3c80b402 | 923 | while (time_before(jiffies, oldstarttime)) { |
0e11c8e8 | 924 | schedule_timeout_interruptible(oldstarttime - jiffies); |
628edaa5 | 925 | stutter_wait("rcu_torture_boost"); |
36970bb9 | 926 | if (torture_must_stop()) |
8e8be45e PM |
927 | goto checkwait; |
928 | } | |
929 | ||
930 | /* Do one boost-test interval. */ | |
931 | endtime = oldstarttime + test_boost_duration * HZ; | |
932 | call_rcu_time = jiffies; | |
3c80b402 | 933 | while (time_before(jiffies, endtime)) { |
8e8be45e | 934 | /* If we don't have a callback in flight, post one. */ |
6c7ed42c PM |
935 | if (!smp_load_acquire(&rbi.inflight)) { |
936 | /* RCU core before ->inflight = 1. */ | |
937 | smp_store_release(&rbi.inflight, 1); | |
8e8be45e | 938 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); |
3b745c89 JFG |
939 | /* Check if the boost test failed */ |
940 | failed = failed || | |
941 | rcu_torture_boost_failed(call_rcu_time, | |
942 | jiffies); | |
8e8be45e PM |
943 | call_rcu_time = jiffies; |
944 | } | |
628edaa5 | 945 | stutter_wait("rcu_torture_boost"); |
36970bb9 | 946 | if (torture_must_stop()) |
8e8be45e PM |
947 | goto checkwait; |
948 | } | |
949 | ||
3b745c89 JFG |
950 | /* |
951 | * If boost never happened, then inflight will always be 1, in | |
952 | * this case the boost check would never happen in the above | |
953 | * loop so do another one here. | |
954 | */ | |
955 | if (!failed && smp_load_acquire(&rbi.inflight)) | |
956 | rcu_torture_boost_failed(call_rcu_time, jiffies); | |
957 | ||
8e8be45e PM |
958 | /* |
959 | * Set the start time of the next test interval. | |
960 | * Yes, this is vulnerable to long delays, but such | |
961 | * delays simply cause a false negative for the next | |
962 | * interval. Besides, we are running at RT priority, | |
963 | * so delays should be relatively rare. | |
964 | */ | |
ab8f11e5 PM |
965 | while (oldstarttime == boost_starttime && |
966 | !kthread_should_stop()) { | |
8e8be45e PM |
967 | if (mutex_trylock(&boost_mutex)) { |
968 | boost_starttime = jiffies + | |
969 | test_boost_interval * HZ; | |
8e8be45e PM |
970 | mutex_unlock(&boost_mutex); |
971 | break; | |
972 | } | |
973 | schedule_timeout_uninterruptible(1); | |
974 | } | |
975 | ||
976 | /* Go do the stutter. */ | |
628edaa5 | 977 | checkwait: stutter_wait("rcu_torture_boost"); |
36970bb9 | 978 | } while (!torture_must_stop()); |
8e8be45e PM |
979 | |
980 | /* Clean up and exit. */ | |
6c7ed42c | 981 | while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) { |
7fafaac5 | 982 | torture_shutdown_absorb("rcu_torture_boost"); |
8e8be45e | 983 | schedule_timeout_uninterruptible(1); |
7fafaac5 | 984 | } |
9d68197c | 985 | destroy_rcu_head_on_stack(&rbi.rcu); |
7fafaac5 | 986 | torture_kthread_stopping("rcu_torture_boost"); |
8e8be45e PM |
987 | return 0; |
988 | } | |
989 | ||
bf66f18e PM |
990 | /* |
991 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
992 | * bursts of calls to force_quiescent_state(), increasing the probability | |
993 | * of occurrence of some important types of race conditions. | |
994 | */ | |
995 | static int | |
996 | rcu_torture_fqs(void *arg) | |
997 | { | |
998 | unsigned long fqs_resume_time; | |
999 | int fqs_burst_remaining; | |
1000 | ||
5ccf60f2 | 1001 | VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); |
bf66f18e PM |
1002 | do { |
1003 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
3c80b402 | 1004 | while (time_before(jiffies, fqs_resume_time) && |
93898fb1 | 1005 | !kthread_should_stop()) { |
bf66f18e PM |
1006 | schedule_timeout_interruptible(1); |
1007 | } | |
1008 | fqs_burst_remaining = fqs_duration; | |
93898fb1 PM |
1009 | while (fqs_burst_remaining > 0 && |
1010 | !kthread_should_stop()) { | |
bf66f18e PM |
1011 | cur_ops->fqs(); |
1012 | udelay(fqs_holdoff); | |
1013 | fqs_burst_remaining -= fqs_holdoff; | |
1014 | } | |
628edaa5 | 1015 | stutter_wait("rcu_torture_fqs"); |
36970bb9 | 1016 | } while (!torture_must_stop()); |
7fafaac5 | 1017 | torture_kthread_stopping("rcu_torture_fqs"); |
bf66f18e PM |
1018 | return 0; |
1019 | } | |
1020 | ||
a241ec65 PM |
1021 | /* |
1022 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
1023 | * for that pointed to by rcu_torture_current, freeing the old structure | |
1024 | * after a series of grace periods (the "pipeline"). | |
1025 | */ | |
1026 | static int | |
1027 | rcu_torture_writer(void *arg) | |
1028 | { | |
9efafb88 | 1029 | bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); |
4bb3c5f4 | 1030 | int expediting = 0; |
a48f3fad PM |
1031 | unsigned long gp_snap; |
1032 | bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal; | |
f0bf8fab | 1033 | bool gp_sync1 = gp_sync; |
a241ec65 | 1034 | int i; |
a241ec65 PM |
1035 | struct rcu_torture *rp; |
1036 | struct rcu_torture *old_rp; | |
51b1130e | 1037 | static DEFINE_TORTURE_RANDOM(rand); |
f0bf8fab PM |
1038 | int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC, |
1039 | RTWS_COND_GET, RTWS_SYNC }; | |
a48f3fad | 1040 | int nsynctypes = 0; |
a241ec65 | 1041 | |
5ccf60f2 | 1042 | VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); |
f7c0e6ad | 1043 | if (!can_expedite) |
aa5a8988 | 1044 | pr_alert("%s" TORTURE_FLAG |
f7c0e6ad | 1045 | " GP expediting controlled from boot/sysfs for %s.\n", |
aa5a8988 | 1046 | torture_type, cur_ops->name); |
dbdf65b1 | 1047 | |
a48f3fad | 1048 | /* Initialize synctype[] array. If none set, take default. */ |
c136f991 | 1049 | if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1) |
f0bf8fab | 1050 | gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true; |
db0c1a8a | 1051 | if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) { |
a48f3fad | 1052 | synctype[nsynctypes++] = RTWS_COND_GET; |
db0c1a8a PM |
1053 | pr_info("%s: Testing conditional GPs.\n", __func__); |
1054 | } else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) { | |
e0d31a34 | 1055 | pr_alert("%s: gp_cond without primitives.\n", __func__); |
db0c1a8a PM |
1056 | } |
1057 | if (gp_exp1 && cur_ops->exp_sync) { | |
a48f3fad | 1058 | synctype[nsynctypes++] = RTWS_EXP_SYNC; |
db0c1a8a PM |
1059 | pr_info("%s: Testing expedited GPs.\n", __func__); |
1060 | } else if (gp_exp && !cur_ops->exp_sync) { | |
e0d31a34 | 1061 | pr_alert("%s: gp_exp without primitives.\n", __func__); |
db0c1a8a PM |
1062 | } |
1063 | if (gp_normal1 && cur_ops->deferred_free) { | |
a48f3fad | 1064 | synctype[nsynctypes++] = RTWS_DEF_FREE; |
db0c1a8a PM |
1065 | pr_info("%s: Testing asynchronous GPs.\n", __func__); |
1066 | } else if (gp_normal && !cur_ops->deferred_free) { | |
e0d31a34 | 1067 | pr_alert("%s: gp_normal without primitives.\n", __func__); |
db0c1a8a PM |
1068 | } |
1069 | if (gp_sync1 && cur_ops->sync) { | |
f0bf8fab | 1070 | synctype[nsynctypes++] = RTWS_SYNC; |
db0c1a8a PM |
1071 | pr_info("%s: Testing normal GPs.\n", __func__); |
1072 | } else if (gp_sync && !cur_ops->sync) { | |
e0d31a34 | 1073 | pr_alert("%s: gp_sync without primitives.\n", __func__); |
db0c1a8a | 1074 | } |
a48f3fad PM |
1075 | if (WARN_ONCE(nsynctypes == 0, |
1076 | "rcu_torture_writer: No update-side primitives.\n")) { | |
f0bf8fab PM |
1077 | /* |
1078 | * No updates primitives, so don't try updating. | |
1079 | * The resulting test won't be testing much, hence the | |
1080 | * above WARN_ONCE(). | |
1081 | */ | |
a48f3fad PM |
1082 | rcu_torture_writer_state = RTWS_STOPPING; |
1083 | torture_kthread_stopping("rcu_torture_writer"); | |
1084 | } | |
1085 | ||
a241ec65 | 1086 | do { |
ad0dc7f9 | 1087 | rcu_torture_writer_state = RTWS_FIXED_DELAY; |
a241ec65 | 1088 | schedule_timeout_uninterruptible(1); |
a71fca58 PM |
1089 | rp = rcu_torture_alloc(); |
1090 | if (rp == NULL) | |
a241ec65 PM |
1091 | continue; |
1092 | rp->rtort_pipe_count = 0; | |
ad0dc7f9 | 1093 | rcu_torture_writer_state = RTWS_DELAY; |
51b1130e | 1094 | udelay(torture_random(&rand) & 0x3ff); |
ad0dc7f9 | 1095 | rcu_torture_writer_state = RTWS_REPLACE; |
0ddea0ea PM |
1096 | old_rp = rcu_dereference_check(rcu_torture_current, |
1097 | current == writer_task); | |
996417d2 | 1098 | rp->rtort_mbtest = 1; |
a241ec65 | 1099 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 1100 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 1101 | if (old_rp) { |
a241ec65 PM |
1102 | i = old_rp->rtort_pipe_count; |
1103 | if (i > RCU_TORTURE_PIPE_LEN) | |
1104 | i = RCU_TORTURE_PIPE_LEN; | |
1105 | atomic_inc(&rcu_torture_wcount[i]); | |
20248910 PM |
1106 | WRITE_ONCE(old_rp->rtort_pipe_count, |
1107 | old_rp->rtort_pipe_count + 1); | |
a48f3fad PM |
1108 | switch (synctype[torture_random(&rand) % nsynctypes]) { |
1109 | case RTWS_DEF_FREE: | |
ad0dc7f9 | 1110 | rcu_torture_writer_state = RTWS_DEF_FREE; |
2ec1f2d9 | 1111 | cur_ops->deferred_free(old_rp); |
a48f3fad PM |
1112 | break; |
1113 | case RTWS_EXP_SYNC: | |
ad0dc7f9 | 1114 | rcu_torture_writer_state = RTWS_EXP_SYNC; |
2ec1f2d9 | 1115 | cur_ops->exp_sync(); |
a48f3fad PM |
1116 | rcu_torture_pipe_update(old_rp); |
1117 | break; | |
1118 | case RTWS_COND_GET: | |
1119 | rcu_torture_writer_state = RTWS_COND_GET; | |
1120 | gp_snap = cur_ops->get_state(); | |
1121 | i = torture_random(&rand) % 16; | |
1122 | if (i != 0) | |
1123 | schedule_timeout_interruptible(i); | |
1124 | udelay(torture_random(&rand) % 1000); | |
1125 | rcu_torture_writer_state = RTWS_COND_SYNC; | |
1126 | cur_ops->cond_sync(gp_snap); | |
1127 | rcu_torture_pipe_update(old_rp); | |
1128 | break; | |
f0bf8fab PM |
1129 | case RTWS_SYNC: |
1130 | rcu_torture_writer_state = RTWS_SYNC; | |
1131 | cur_ops->sync(); | |
1132 | rcu_torture_pipe_update(old_rp); | |
1133 | break; | |
a48f3fad PM |
1134 | default: |
1135 | WARN_ON_ONCE(1); | |
1136 | break; | |
2ec1f2d9 | 1137 | } |
a241ec65 | 1138 | } |
1b27291b PM |
1139 | WRITE_ONCE(rcu_torture_current_version, |
1140 | rcu_torture_current_version + 1); | |
4bb3c5f4 PM |
1141 | /* Cycle through nesting levels of rcu_expedite_gp() calls. */ |
1142 | if (can_expedite && | |
1143 | !(torture_random(&rand) & 0xff & (!!expediting - 1))) { | |
1144 | WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); | |
1145 | if (expediting >= 0) | |
1146 | rcu_expedite_gp(); | |
1147 | else | |
1148 | rcu_unexpedite_gp(); | |
1149 | if (++expediting > 3) | |
1150 | expediting = -expediting; | |
f7c0e6ad PM |
1151 | } else if (!can_expedite) { /* Disabled during boot, recheck. */ |
1152 | can_expedite = !rcu_gp_is_expedited() && | |
1153 | !rcu_gp_is_normal(); | |
4bb3c5f4 | 1154 | } |
ad0dc7f9 | 1155 | rcu_torture_writer_state = RTWS_STUTTER; |
e8516c64 | 1156 | if (stutter_wait("rcu_torture_writer") && |
5eabea59 | 1157 | !READ_ONCE(rcu_fwd_cb_nodelay) && |
3432d765 | 1158 | !cur_ops->slow_gps && |
59ee0326 PM |
1159 | !torture_must_stop() && |
1160 | rcu_inkernel_boot_has_ended()) | |
474e59b4 | 1161 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) |
e8516c64 PM |
1162 | if (list_empty(&rcu_tortures[i].rtort_free) && |
1163 | rcu_access_pointer(rcu_torture_current) != | |
34aa34b8 PM |
1164 | &rcu_tortures[i]) { |
1165 | rcu_ftrace_dump(DUMP_ALL); | |
e8516c64 | 1166 | WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); |
34aa34b8 | 1167 | } |
36970bb9 | 1168 | } while (!torture_must_stop()); |
4bb3c5f4 PM |
1169 | /* Reset expediting back to unexpedited. */ |
1170 | if (expediting > 0) | |
1171 | expediting = -expediting; | |
1172 | while (can_expedite && expediting++ < 0) | |
1173 | rcu_unexpedite_gp(); | |
1174 | WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); | |
f7c0e6ad PM |
1175 | if (!can_expedite) |
1176 | pr_alert("%s" TORTURE_FLAG | |
1177 | " Dynamic grace-period expediting was disabled.\n", | |
1178 | torture_type); | |
ad0dc7f9 | 1179 | rcu_torture_writer_state = RTWS_STOPPING; |
7fafaac5 | 1180 | torture_kthread_stopping("rcu_torture_writer"); |
a241ec65 PM |
1181 | return 0; |
1182 | } | |
1183 | ||
b772e1dd JT |
1184 | /* |
1185 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
1186 | * delay between calls. | |
1187 | */ | |
1188 | static int | |
1189 | rcu_torture_fakewriter(void *arg) | |
1190 | { | |
51b1130e | 1191 | DEFINE_TORTURE_RANDOM(rand); |
b772e1dd | 1192 | |
5ccf60f2 | 1193 | VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); |
d277d868 | 1194 | set_user_nice(current, MAX_NICE); |
b772e1dd JT |
1195 | |
1196 | do { | |
51b1130e PM |
1197 | schedule_timeout_uninterruptible(1 + torture_random(&rand)%10); |
1198 | udelay(torture_random(&rand) & 0x3ff); | |
72472a02 | 1199 | if (cur_ops->cb_barrier != NULL && |
51b1130e | 1200 | torture_random(&rand) % (nfakewriters * 8) == 0) { |
72472a02 | 1201 | cur_ops->cb_barrier(); |
2ec1f2d9 | 1202 | } else if (gp_normal == gp_exp) { |
eb033993 | 1203 | if (cur_ops->sync && torture_random(&rand) & 0x80) |
2ec1f2d9 | 1204 | cur_ops->sync(); |
eb033993 | 1205 | else if (cur_ops->exp_sync) |
2ec1f2d9 | 1206 | cur_ops->exp_sync(); |
eb033993 | 1207 | } else if (gp_normal && cur_ops->sync) { |
72472a02 | 1208 | cur_ops->sync(); |
eb033993 | 1209 | } else if (cur_ops->exp_sync) { |
2ec1f2d9 PM |
1210 | cur_ops->exp_sync(); |
1211 | } | |
628edaa5 | 1212 | stutter_wait("rcu_torture_fakewriter"); |
36970bb9 | 1213 | } while (!torture_must_stop()); |
b772e1dd | 1214 | |
7fafaac5 | 1215 | torture_kthread_stopping("rcu_torture_fakewriter"); |
b772e1dd JT |
1216 | return 0; |
1217 | } | |
1218 | ||
f34c8585 PM |
1219 | static void rcu_torture_timer_cb(struct rcu_head *rhp) |
1220 | { | |
1221 | kfree(rhp); | |
1222 | } | |
1223 | ||
0729fbf3 | 1224 | /* |
2397d072 PM |
1225 | * Do one extension of an RCU read-side critical section using the |
1226 | * current reader state in readstate (set to zero for initial entry | |
1227 | * to extended critical section), set the new state as specified by | |
1228 | * newstate (set to zero for final exit from extended critical section), | |
1229 | * and random-number-generator state in trsp. If this is neither the | |
1230 | * beginning or end of the critical section and if there was actually a | |
1231 | * change, do a ->read_delay(). | |
0729fbf3 | 1232 | */ |
2397d072 | 1233 | static void rcutorture_one_extend(int *readstate, int newstate, |
c116dba6 PM |
1234 | struct torture_random_state *trsp, |
1235 | struct rt_read_seg *rtrsp) | |
2397d072 | 1236 | { |
52b1fc3f | 1237 | unsigned long flags; |
2397d072 PM |
1238 | int idxnew = -1; |
1239 | int idxold = *readstate; | |
1240 | int statesnew = ~*readstate & newstate; | |
1241 | int statesold = *readstate & ~newstate; | |
1242 | ||
1243 | WARN_ON_ONCE(idxold < 0); | |
1244 | WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 1); | |
c116dba6 | 1245 | rtrsp->rt_readstate = newstate; |
2397d072 PM |
1246 | |
1247 | /* First, put new protection in place to avoid critical-section gap. */ | |
1248 | if (statesnew & RCUTORTURE_RDR_BH) | |
1249 | local_bh_disable(); | |
1250 | if (statesnew & RCUTORTURE_RDR_IRQ) | |
1251 | local_irq_disable(); | |
1252 | if (statesnew & RCUTORTURE_RDR_PREEMPT) | |
1253 | preempt_disable(); | |
2ceebc03 PM |
1254 | if (statesnew & RCUTORTURE_RDR_RBH) |
1255 | rcu_read_lock_bh(); | |
1256 | if (statesnew & RCUTORTURE_RDR_SCHED) | |
1257 | rcu_read_lock_sched(); | |
2397d072 PM |
1258 | if (statesnew & RCUTORTURE_RDR_RCU) |
1259 | idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT; | |
1260 | ||
1261 | /* Next, remove old protection, irq first due to bh conflict. */ | |
1262 | if (statesold & RCUTORTURE_RDR_IRQ) | |
1263 | local_irq_enable(); | |
1264 | if (statesold & RCUTORTURE_RDR_BH) | |
1265 | local_bh_enable(); | |
1266 | if (statesold & RCUTORTURE_RDR_PREEMPT) | |
1267 | preempt_enable(); | |
2ceebc03 PM |
1268 | if (statesold & RCUTORTURE_RDR_RBH) |
1269 | rcu_read_unlock_bh(); | |
1270 | if (statesold & RCUTORTURE_RDR_SCHED) | |
1271 | rcu_read_unlock_sched(); | |
52b1fc3f PM |
1272 | if (statesold & RCUTORTURE_RDR_RCU) { |
1273 | bool lockit = !statesnew && !(torture_random(trsp) & 0xffff); | |
1274 | ||
1275 | if (lockit) | |
1276 | raw_spin_lock_irqsave(¤t->pi_lock, flags); | |
2397d072 | 1277 | cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT); |
52b1fc3f PM |
1278 | if (lockit) |
1279 | raw_spin_unlock_irqrestore(¤t->pi_lock, flags); | |
1280 | } | |
2397d072 PM |
1281 | |
1282 | /* Delay if neither beginning nor end and there was a change. */ | |
1283 | if ((statesnew || statesold) && *readstate && newstate) | |
c116dba6 | 1284 | cur_ops->read_delay(trsp, rtrsp); |
2397d072 PM |
1285 | |
1286 | /* Update the reader state. */ | |
1287 | if (idxnew == -1) | |
1288 | idxnew = idxold & ~RCUTORTURE_RDR_MASK; | |
1289 | WARN_ON_ONCE(idxnew < 0); | |
1290 | WARN_ON_ONCE((idxnew >> RCUTORTURE_RDR_SHIFT) > 1); | |
1291 | *readstate = idxnew | newstate; | |
1292 | WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) < 0); | |
1293 | WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) > 1); | |
1294 | } | |
1295 | ||
1296 | /* Return the biggest extendables mask given current RCU and boot parameters. */ | |
1297 | static int rcutorture_extend_mask_max(void) | |
1298 | { | |
1299 | int mask; | |
1300 | ||
1301 | WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); | |
1302 | mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; | |
1303 | mask = mask | RCUTORTURE_RDR_RCU; | |
1304 | return mask; | |
1305 | } | |
1306 | ||
1307 | /* Return a random protection state mask, but with at least one bit set. */ | |
1308 | static int | |
1309 | rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) | |
1310 | { | |
1311 | int mask = rcutorture_extend_mask_max(); | |
bf1bef50 | 1312 | unsigned long randmask1 = torture_random(trsp) >> 8; |
c116dba6 | 1313 | unsigned long randmask2 = randmask1 >> 3; |
2397d072 PM |
1314 | |
1315 | WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT); | |
a3b0e1e5 | 1316 | /* Mostly only one bit (need preemption!), sometimes lots of bits. */ |
c116dba6 | 1317 | if (!(randmask1 & 0x7)) |
bf1bef50 PM |
1318 | mask = mask & randmask2; |
1319 | else | |
1320 | mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); | |
2ceebc03 | 1321 | /* Can't enable bh w/irq disabled. */ |
2397d072 | 1322 | if ((mask & RCUTORTURE_RDR_IRQ) && |
2ceebc03 PM |
1323 | ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) || |
1324 | (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH)))) | |
1325 | mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; | |
2397d072 PM |
1326 | return mask ?: RCUTORTURE_RDR_RCU; |
1327 | } | |
1328 | ||
1329 | /* | |
1330 | * Do a randomly selected number of extensions of an existing RCU read-side | |
1331 | * critical section. | |
1332 | */ | |
c116dba6 PM |
1333 | static struct rt_read_seg * |
1334 | rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, | |
1335 | struct rt_read_seg *rtrsp) | |
2397d072 PM |
1336 | { |
1337 | int i; | |
c116dba6 | 1338 | int j; |
2397d072 PM |
1339 | int mask = rcutorture_extend_mask_max(); |
1340 | ||
1341 | WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ | |
1342 | if (!((mask - 1) & mask)) | |
c116dba6 PM |
1343 | return rtrsp; /* Current RCU reader not extendable. */ |
1344 | /* Bias towards larger numbers of loops. */ | |
1345 | i = (torture_random(trsp) >> 3); | |
1346 | i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; | |
1347 | for (j = 0; j < i; j++) { | |
2397d072 | 1348 | mask = rcutorture_extend_mask(*readstate, trsp); |
c116dba6 | 1349 | rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); |
2397d072 | 1350 | } |
c116dba6 | 1351 | return &rtrsp[j]; |
2397d072 PM |
1352 | } |
1353 | ||
6b06aa72 PM |
1354 | /* |
1355 | * Do one read-side critical section, returning false if there was | |
1356 | * no data to read. Can be invoked both from process context and | |
1357 | * from a timer handler. | |
1358 | */ | |
1359 | static bool rcu_torture_one_read(struct torture_random_state *trsp) | |
0729fbf3 | 1360 | { |
c116dba6 | 1361 | int i; |
917963d0 | 1362 | unsigned long started; |
6b80da42 | 1363 | unsigned long completed; |
2397d072 | 1364 | int newstate; |
0729fbf3 PM |
1365 | struct rcu_torture *p; |
1366 | int pipe_count; | |
2397d072 | 1367 | int readstate = 0; |
c116dba6 PM |
1368 | struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } }; |
1369 | struct rt_read_seg *rtrsp = &rtseg[0]; | |
1370 | struct rt_read_seg *rtrsp1; | |
52494535 | 1371 | unsigned long long ts; |
0729fbf3 | 1372 | |
2397d072 | 1373 | newstate = rcutorture_extend_mask(readstate, trsp); |
c116dba6 | 1374 | rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++); |
17ef2fe9 | 1375 | started = cur_ops->get_gp_seq(); |
e4aa0da3 | 1376 | ts = rcu_trace_clock_local(); |
632ee200 | 1377 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
1378 | rcu_read_lock_bh_held() || |
1379 | rcu_read_lock_sched_held() || | |
5be5d1a1 | 1380 | srcu_read_lock_held(srcu_ctlp) || |
c1a76c0b | 1381 | rcu_read_lock_trace_held() || |
5be5d1a1 | 1382 | torturing_tasks()); |
0729fbf3 | 1383 | if (p == NULL) { |
6b06aa72 | 1384 | /* Wait for rcu_torture_writer to get underway */ |
c116dba6 | 1385 | rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
6b06aa72 | 1386 | return false; |
0729fbf3 PM |
1387 | } |
1388 | if (p->rtort_mbtest == 0) | |
1389 | atomic_inc(&n_rcu_torture_mberror); | |
c116dba6 | 1390 | rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp); |
0729fbf3 | 1391 | preempt_disable(); |
20248910 | 1392 | pipe_count = READ_ONCE(p->rtort_pipe_count); |
0729fbf3 PM |
1393 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { |
1394 | /* Should not happen, but... */ | |
1395 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1396 | } | |
17ef2fe9 | 1397 | completed = cur_ops->get_gp_seq(); |
52494535 | 1398 | if (pipe_count > 1) { |
6b06aa72 PM |
1399 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, |
1400 | ts, started, completed); | |
274529ba | 1401 | rcu_ftrace_dump(DUMP_ALL); |
52494535 | 1402 | } |
dd17c8f7 | 1403 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
d7219312 | 1404 | completed = rcutorture_seq_diff(completed, started); |
0729fbf3 PM |
1405 | if (completed > RCU_TORTURE_PIPE_LEN) { |
1406 | /* Should not happen, but... */ | |
1407 | completed = RCU_TORTURE_PIPE_LEN; | |
1408 | } | |
dd17c8f7 | 1409 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 | 1410 | preempt_enable(); |
c116dba6 | 1411 | rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
2397d072 | 1412 | WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK); |
c116dba6 PM |
1413 | |
1414 | /* If error or close call, record the sequence of reader protections. */ | |
1415 | if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { | |
1416 | i = 0; | |
1417 | for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++) | |
1418 | err_segs[i++] = *rtrsp1; | |
1419 | rt_read_nsegs = i; | |
1420 | } | |
1421 | ||
6b06aa72 PM |
1422 | return true; |
1423 | } | |
1424 | ||
3025520e PM |
1425 | static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); |
1426 | ||
0729fbf3 PM |
1427 | /* |
1428 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
1429 | * incrementing the corresponding element of the pipeline array. The | |
1430 | * counter in the element should never be greater than 1, otherwise, the | |
1431 | * RCU implementation is broken. | |
1432 | */ | |
fd30b717 | 1433 | static void rcu_torture_timer(struct timer_list *unused) |
0729fbf3 | 1434 | { |
8da9a595 | 1435 | atomic_long_inc(&n_rcu_torture_timers); |
241b4252 | 1436 | (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand)); |
f34c8585 PM |
1437 | |
1438 | /* Test call_rcu() invocation from interrupt handler. */ | |
1439 | if (cur_ops->call) { | |
1440 | struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT); | |
1441 | ||
1442 | if (rhp) | |
1443 | cur_ops->call(rhp, rcu_torture_timer_cb); | |
1444 | } | |
0729fbf3 PM |
1445 | } |
1446 | ||
a241ec65 PM |
1447 | /* |
1448 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
1449 | * incrementing the corresponding element of the pipeline array. The | |
1450 | * counter in the element should never be greater than 1, otherwise, the | |
1451 | * RCU implementation is broken. | |
1452 | */ | |
1453 | static int | |
1454 | rcu_torture_reader(void *arg) | |
1455 | { | |
444da518 | 1456 | unsigned long lastsleep = jiffies; |
c04dd09b PM |
1457 | long myid = (long)arg; |
1458 | int mynumonline = myid; | |
51b1130e | 1459 | DEFINE_TORTURE_RANDOM(rand); |
0729fbf3 | 1460 | struct timer_list t; |
a241ec65 | 1461 | |
5ccf60f2 | 1462 | VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); |
d277d868 | 1463 | set_user_nice(current, MAX_NICE); |
0acc512c | 1464 | if (irqreader && cur_ops->irq_capable) |
fd30b717 | 1465 | timer_setup_on_stack(&t, rcu_torture_timer, 0); |
d38e6dc6 | 1466 | tick_dep_set_task(current, TICK_DEP_BIT_RCU); |
a241ec65 | 1467 | do { |
0acc512c | 1468 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1469 | if (!timer_pending(&t)) |
6155fec9 | 1470 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 1471 | } |
d38e6dc6 | 1472 | if (!rcu_torture_one_read(&rand) && !torture_must_stop()) |
a241ec65 | 1473 | schedule_timeout_interruptible(HZ); |
d38e6dc6 | 1474 | if (time_after(jiffies, lastsleep) && !torture_must_stop()) { |
444da518 PM |
1475 | schedule_timeout_interruptible(1); |
1476 | lastsleep = jiffies + 10; | |
1477 | } | |
c04dd09b PM |
1478 | while (num_online_cpus() < mynumonline && !torture_must_stop()) |
1479 | schedule_timeout_interruptible(HZ / 5); | |
628edaa5 | 1480 | stutter_wait("rcu_torture_reader"); |
36970bb9 | 1481 | } while (!torture_must_stop()); |
424c1b68 | 1482 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1483 | del_timer_sync(&t); |
424c1b68 TG |
1484 | destroy_timer_on_stack(&t); |
1485 | } | |
d38e6dc6 | 1486 | tick_dep_clear_task(current, TICK_DEP_BIT_RCU); |
7fafaac5 | 1487 | torture_kthread_stopping("rcu_torture_reader"); |
a241ec65 PM |
1488 | return 0; |
1489 | } | |
1490 | ||
1491 | /* | |
eea203fe JP |
1492 | * Print torture statistics. Caller must ensure that there is only |
1493 | * one call to this function at a given time!!! This is normally | |
1494 | * accomplished by relying on the module system to only have one copy | |
1495 | * of the module loaded, and then by giving the rcu_torture_stats | |
1496 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1497 | * thread is not running). | |
a241ec65 | 1498 | */ |
d1008950 | 1499 | static void |
eea203fe | 1500 | rcu_torture_stats_print(void) |
a241ec65 | 1501 | { |
a241ec65 PM |
1502 | int cpu; |
1503 | int i; | |
1504 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1505 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
5396d31d | 1506 | struct rcu_torture *rtcp; |
ad0dc7f9 | 1507 | static unsigned long rtcv_snap = ULONG_MAX; |
0032f4e8 | 1508 | static bool splatted; |
4ffa6699 | 1509 | struct task_struct *wtp; |
a241ec65 | 1510 | |
0a945022 | 1511 | for_each_possible_cpu(cpu) { |
a241ec65 | 1512 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
f042a436 PM |
1513 | pipesummary[i] += READ_ONCE(per_cpu(rcu_torture_count, cpu)[i]); |
1514 | batchsummary[i] += READ_ONCE(per_cpu(rcu_torture_batch, cpu)[i]); | |
a241ec65 PM |
1515 | } |
1516 | } | |
1517 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1518 | if (pipesummary[i] != 0) | |
1519 | break; | |
1520 | } | |
eea203fe JP |
1521 | |
1522 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
5396d31d | 1523 | rtcp = rcu_access_pointer(rcu_torture_current); |
354ea05d | 1524 | pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", |
5396d31d PM |
1525 | rtcp, |
1526 | rtcp && !rcu_stall_is_suppressed_at_boot() ? "ver" : "VER", | |
eea203fe JP |
1527 | rcu_torture_current_version, |
1528 | list_empty(&rcu_torture_freelist), | |
1529 | atomic_read(&n_rcu_torture_alloc), | |
1530 | atomic_read(&n_rcu_torture_alloc_fail), | |
1531 | atomic_read(&n_rcu_torture_free)); | |
472213a6 | 1532 | pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ", |
eea203fe | 1533 | atomic_read(&n_rcu_torture_mberror), |
472213a6 | 1534 | n_rcu_torture_barrier_error, |
eea203fe JP |
1535 | n_rcu_torture_boost_ktrerror, |
1536 | n_rcu_torture_boost_rterror); | |
1537 | pr_cont("rtbf: %ld rtb: %ld nt: %ld ", | |
1538 | n_rcu_torture_boost_failure, | |
1539 | n_rcu_torture_boosts, | |
8da9a595 | 1540 | atomic_long_read(&n_rcu_torture_timers)); |
eea203fe | 1541 | torture_onoff_stats(); |
fc6f9c57 | 1542 | pr_cont("barrier: %ld/%ld:%ld\n", |
c9527beb PM |
1543 | data_race(n_barrier_successes), |
1544 | data_race(n_barrier_attempts), | |
1545 | data_race(n_rcu_torture_barrier_error)); | |
eea203fe JP |
1546 | |
1547 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
8b5ddf8b PM |
1548 | if (atomic_read(&n_rcu_torture_mberror) || |
1549 | n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || | |
1550 | n_rcu_torture_boost_rterror || n_rcu_torture_boost_failure || | |
fae4b54f | 1551 | i > 1) { |
eea203fe | 1552 | pr_cont("%s", "!!! "); |
996417d2 | 1553 | atomic_inc(&n_rcu_torture_error); |
8b5ddf8b PM |
1554 | WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); |
1555 | WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() | |
1556 | WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread | |
1557 | WARN_ON_ONCE(n_rcu_torture_boost_rterror); // can't set RT prio | |
1558 | WARN_ON_ONCE(n_rcu_torture_boost_failure); // RCU boost failed | |
1559 | WARN_ON_ONCE(i > 1); // Too-short grace period | |
996417d2 | 1560 | } |
eea203fe | 1561 | pr_cont("Reader Pipe: "); |
a241ec65 | 1562 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
eea203fe JP |
1563 | pr_cont(" %ld", pipesummary[i]); |
1564 | pr_cont("\n"); | |
1565 | ||
1566 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
1567 | pr_cont("Reader Batch: "); | |
72e9bb54 | 1568 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
eea203fe JP |
1569 | pr_cont(" %ld", batchsummary[i]); |
1570 | pr_cont("\n"); | |
1571 | ||
1572 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
1573 | pr_cont("Free-Block Circulation: "); | |
a241ec65 | 1574 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
eea203fe | 1575 | pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); |
a241ec65 | 1576 | } |
eea203fe JP |
1577 | pr_cont("\n"); |
1578 | ||
c8e5b163 | 1579 | if (cur_ops->stats) |
eea203fe | 1580 | cur_ops->stats(); |
ad0dc7f9 | 1581 | if (rtcv_snap == rcu_torture_current_version && |
5396d31d PM |
1582 | rcu_access_pointer(rcu_torture_current) && |
1583 | !rcu_stall_is_suppressed()) { | |
7f6733c3 | 1584 | int __maybe_unused flags = 0; |
aebc8264 | 1585 | unsigned long __maybe_unused gp_seq = 0; |
ad0dc7f9 PM |
1586 | |
1587 | rcutorture_get_gp_data(cur_ops->ttype, | |
aebc8264 | 1588 | &flags, &gp_seq); |
7f6733c3 | 1589 | srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, |
aebc8264 | 1590 | &flags, &gp_seq); |
4ffa6699 | 1591 | wtp = READ_ONCE(writer_task); |
aebc8264 | 1592 | pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n", |
18aff33e | 1593 | rcu_torture_writer_state_getname(), |
aebc8264 | 1594 | rcu_torture_writer_state, gp_seq, flags, |
808de39c PM |
1595 | wtp == NULL ? ~0UL : wtp->state, |
1596 | wtp == NULL ? -1 : (int)task_cpu(wtp)); | |
0032f4e8 PM |
1597 | if (!splatted && wtp) { |
1598 | sched_show_task(wtp); | |
1599 | splatted = true; | |
1600 | } | |
afea227f | 1601 | show_rcu_gp_kthreads(); |
274529ba | 1602 | rcu_ftrace_dump(DUMP_ALL); |
ad0dc7f9 PM |
1603 | } |
1604 | rtcv_snap = rcu_torture_current_version; | |
a241ec65 PM |
1605 | } |
1606 | ||
a241ec65 PM |
1607 | /* |
1608 | * Periodically prints torture statistics, if periodic statistics printing | |
1609 | * was specified via the stat_interval module parameter. | |
a241ec65 PM |
1610 | */ |
1611 | static int | |
1612 | rcu_torture_stats(void *arg) | |
1613 | { | |
5ccf60f2 | 1614 | VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); |
a241ec65 PM |
1615 | do { |
1616 | schedule_timeout_interruptible(stat_interval * HZ); | |
1617 | rcu_torture_stats_print(); | |
f67a3356 | 1618 | torture_shutdown_absorb("rcu_torture_stats"); |
36970bb9 | 1619 | } while (!torture_must_stop()); |
7fafaac5 | 1620 | torture_kthread_stopping("rcu_torture_stats"); |
d120f65f PM |
1621 | return 0; |
1622 | } | |
1623 | ||
eac45e58 | 1624 | static void |
e66c33d5 | 1625 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) |
95c38322 | 1626 | { |
2caa1e44 PM |
1627 | pr_alert("%s" TORTURE_FLAG |
1628 | "--- %s: nreaders=%d nfakewriters=%d " | |
1629 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
1630 | "shuffle_interval=%d stutter=%d irqreader=%d " | |
1631 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " | |
1632 | "test_boost=%d/%d test_boost_interval=%d " | |
1633 | "test_boost_duration=%d shutdown_secs=%d " | |
2b1516e5 | 1634 | "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " |
19a8ff95 | 1635 | "stall_cpu_block=%d " |
67afeed2 | 1636 | "n_barrier_cbs=%d " |
2caa1e44 PM |
1637 | "onoff_interval=%d onoff_holdoff=%d\n", |
1638 | torture_type, tag, nrealreaders, nfakewriters, | |
1639 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, | |
1640 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, | |
1641 | test_boost, cur_ops->can_boost, | |
1642 | test_boost_interval, test_boost_duration, shutdown_secs, | |
2b1516e5 | 1643 | stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, |
19a8ff95 | 1644 | stall_cpu_block, |
67afeed2 | 1645 | n_barrier_cbs, |
2caa1e44 | 1646 | onoff_interval, onoff_holdoff); |
95c38322 PM |
1647 | } |
1648 | ||
0ffd374b | 1649 | static int rcutorture_booster_cleanup(unsigned int cpu) |
8e8be45e PM |
1650 | { |
1651 | struct task_struct *t; | |
1652 | ||
1653 | if (boost_tasks[cpu] == NULL) | |
0ffd374b | 1654 | return 0; |
8e8be45e | 1655 | mutex_lock(&boost_mutex); |
8e8be45e PM |
1656 | t = boost_tasks[cpu]; |
1657 | boost_tasks[cpu] = NULL; | |
450efca7 | 1658 | rcu_torture_enable_rt_throttle(); |
8e8be45e PM |
1659 | mutex_unlock(&boost_mutex); |
1660 | ||
1661 | /* This must be outside of the mutex, otherwise deadlock! */ | |
9c029b86 | 1662 | torture_stop_kthread(rcu_torture_boost, t); |
0ffd374b | 1663 | return 0; |
8e8be45e PM |
1664 | } |
1665 | ||
0ffd374b | 1666 | static int rcutorture_booster_init(unsigned int cpu) |
8e8be45e PM |
1667 | { |
1668 | int retval; | |
1669 | ||
1670 | if (boost_tasks[cpu] != NULL) | |
1671 | return 0; /* Already created, nothing more to do. */ | |
1672 | ||
1673 | /* Don't allow time recalculation while creating a new task. */ | |
1674 | mutex_lock(&boost_mutex); | |
450efca7 | 1675 | rcu_torture_disable_rt_throttle(); |
5ccf60f2 | 1676 | VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); |
1f288094 ED |
1677 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, |
1678 | cpu_to_node(cpu), | |
1679 | "rcu_torture_boost"); | |
8e8be45e PM |
1680 | if (IS_ERR(boost_tasks[cpu])) { |
1681 | retval = PTR_ERR(boost_tasks[cpu]); | |
5ccf60f2 | 1682 | VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); |
8e8be45e PM |
1683 | n_rcu_torture_boost_ktrerror++; |
1684 | boost_tasks[cpu] = NULL; | |
1685 | mutex_unlock(&boost_mutex); | |
1686 | return retval; | |
1687 | } | |
1688 | kthread_bind(boost_tasks[cpu], cpu); | |
1689 | wake_up_process(boost_tasks[cpu]); | |
1690 | mutex_unlock(&boost_mutex); | |
1691 | return 0; | |
1692 | } | |
1693 | ||
c13f3757 PM |
1694 | /* |
1695 | * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then | |
1696 | * induces a CPU stall for the time specified by stall_cpu. | |
1697 | */ | |
49fb4c62 | 1698 | static int rcu_torture_stall(void *args) |
c13f3757 | 1699 | { |
19a8ff95 | 1700 | int idx; |
c13f3757 PM |
1701 | unsigned long stop_at; |
1702 | ||
5ccf60f2 | 1703 | VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); |
c13f3757 | 1704 | if (stall_cpu_holdoff > 0) { |
5ccf60f2 | 1705 | VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); |
c13f3757 | 1706 | schedule_timeout_interruptible(stall_cpu_holdoff * HZ); |
5ccf60f2 | 1707 | VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); |
c13f3757 | 1708 | } |
55b2dcf5 PM |
1709 | if (!kthread_should_stop() && stall_gp_kthread > 0) { |
1710 | VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall"); | |
1711 | rcu_gp_set_torture_wait(stall_gp_kthread * HZ); | |
1712 | for (idx = 0; idx < stall_gp_kthread + 2; idx++) { | |
1713 | if (kthread_should_stop()) | |
1714 | break; | |
1715 | schedule_timeout_uninterruptible(HZ); | |
1716 | } | |
1717 | } | |
1718 | if (!kthread_should_stop() && stall_cpu > 0) { | |
1719 | VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall"); | |
622be33f | 1720 | stop_at = ktime_get_seconds() + stall_cpu; |
c13f3757 | 1721 | /* RCU CPU stall is expected behavior in following code. */ |
19a8ff95 | 1722 | idx = cur_ops->readlock(); |
2b1516e5 PM |
1723 | if (stall_cpu_irqsoff) |
1724 | local_irq_disable(); | |
19a8ff95 | 1725 | else if (!stall_cpu_block) |
2b1516e5 PM |
1726 | preempt_disable(); |
1727 | pr_alert("rcu_torture_stall start on CPU %d.\n", | |
19a8ff95 | 1728 | raw_smp_processor_id()); |
622be33f AB |
1729 | while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), |
1730 | stop_at)) | |
19a8ff95 PM |
1731 | if (stall_cpu_block) |
1732 | schedule_timeout_uninterruptible(HZ); | |
2b1516e5 PM |
1733 | if (stall_cpu_irqsoff) |
1734 | local_irq_enable(); | |
19a8ff95 | 1735 | else if (!stall_cpu_block) |
2b1516e5 | 1736 | preempt_enable(); |
19a8ff95 | 1737 | cur_ops->readunlock(idx); |
c13f3757 | 1738 | } |
55b2dcf5 | 1739 | pr_alert("rcu_torture_stall end.\n"); |
f67a3356 | 1740 | torture_shutdown_absorb("rcu_torture_stall"); |
c13f3757 PM |
1741 | while (!kthread_should_stop()) |
1742 | schedule_timeout_interruptible(10 * HZ); | |
1743 | return 0; | |
1744 | } | |
1745 | ||
1746 | /* Spawn CPU-stall kthread, if stall_cpu specified. */ | |
1747 | static int __init rcu_torture_stall_init(void) | |
1748 | { | |
55b2dcf5 | 1749 | if (stall_cpu <= 0 && stall_gp_kthread <= 0) |
c13f3757 | 1750 | return 0; |
47cf29b9 | 1751 | return torture_create_kthread(rcu_torture_stall, NULL, stall_task); |
c13f3757 PM |
1752 | } |
1753 | ||
9fdcb9af PM |
1754 | /* State structure for forward-progress self-propagating RCU callback. */ |
1755 | struct fwd_cb_state { | |
1756 | struct rcu_head rh; | |
1757 | int stop; | |
1758 | }; | |
1759 | ||
1760 | /* | |
1761 | * Forward-progress self-propagating RCU callback function. Because | |
1762 | * callbacks run from softirq, this function is an implicit RCU read-side | |
1763 | * critical section. | |
1764 | */ | |
1765 | static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) | |
1766 | { | |
1767 | struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); | |
1768 | ||
1769 | if (READ_ONCE(fcsp->stop)) { | |
1770 | WRITE_ONCE(fcsp->stop, 2); | |
1771 | return; | |
1772 | } | |
1773 | cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); | |
1774 | } | |
1775 | ||
48718485 PM |
1776 | /* State for continuous-flood RCU callbacks. */ |
1777 | struct rcu_fwd_cb { | |
1778 | struct rcu_head rh; | |
1779 | struct rcu_fwd_cb *rfc_next; | |
6b1b8325 | 1780 | struct rcu_fwd *rfc_rfp; |
48718485 PM |
1781 | int rfc_gps; |
1782 | }; | |
a289e608 | 1783 | |
48718485 PM |
1784 | #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ |
1785 | #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ | |
1786 | #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ | |
2e57bf97 | 1787 | #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ |
a289e608 PM |
1788 | #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) |
1789 | ||
cd618d10 PM |
1790 | struct rcu_launder_hist { |
1791 | long n_launders; | |
1792 | unsigned long launder_gp_seq; | |
1793 | }; | |
48718485 | 1794 | |
a289e608 PM |
1795 | struct rcu_fwd { |
1796 | spinlock_t rcu_fwd_lock; | |
1797 | struct rcu_fwd_cb *rcu_fwd_cb_head; | |
1798 | struct rcu_fwd_cb **rcu_fwd_cb_tail; | |
1799 | long n_launders_cb; | |
1800 | unsigned long rcu_fwd_startat; | |
1801 | struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; | |
1802 | unsigned long rcu_launder_gp_seq_start; | |
1803 | }; | |
1804 | ||
afbc1574 JY |
1805 | static struct rcu_fwd *rcu_fwds; |
1806 | static bool rcu_fwd_emergency_stop; | |
48718485 | 1807 | |
6b1b8325 | 1808 | static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp) |
1a682754 | 1809 | { |
cd618d10 PM |
1810 | unsigned long gps; |
1811 | unsigned long gps_old; | |
1a682754 PM |
1812 | int i; |
1813 | int j; | |
1814 | ||
6b1b8325 PM |
1815 | for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--) |
1816 | if (rfp->n_launders_hist[i].n_launders > 0) | |
1a682754 | 1817 | break; |
73d665b1 | 1818 | pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):", |
6b1b8325 PM |
1819 | __func__, jiffies - rfp->rcu_fwd_startat); |
1820 | gps_old = rfp->rcu_launder_gp_seq_start; | |
cd618d10 | 1821 | for (j = 0; j <= i; j++) { |
6b1b8325 | 1822 | gps = rfp->n_launders_hist[j].launder_gp_seq; |
cd618d10 | 1823 | pr_cont(" %ds/%d: %ld:%ld", |
a289e608 | 1824 | j + 1, FWD_CBS_HIST_DIV, |
6b1b8325 | 1825 | rfp->n_launders_hist[j].n_launders, |
cd618d10 PM |
1826 | rcutorture_seq_diff(gps, gps_old)); |
1827 | gps_old = gps; | |
1828 | } | |
1a682754 PM |
1829 | pr_cont("\n"); |
1830 | } | |
1831 | ||
48718485 PM |
1832 | /* Callback function for continuous-flood RCU callbacks. */ |
1833 | static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) | |
1834 | { | |
2667ccce | 1835 | unsigned long flags; |
48718485 PM |
1836 | int i; |
1837 | struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); | |
1838 | struct rcu_fwd_cb **rfcpp; | |
6b1b8325 | 1839 | struct rcu_fwd *rfp = rfcp->rfc_rfp; |
48718485 PM |
1840 | |
1841 | rfcp->rfc_next = NULL; | |
1842 | rfcp->rfc_gps++; | |
6b1b8325 PM |
1843 | spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); |
1844 | rfcpp = rfp->rcu_fwd_cb_tail; | |
1845 | rfp->rcu_fwd_cb_tail = &rfcp->rfc_next; | |
48718485 | 1846 | WRITE_ONCE(*rfcpp, rfcp); |
6b1b8325 PM |
1847 | WRITE_ONCE(rfp->n_launders_cb, rfp->n_launders_cb + 1); |
1848 | i = ((jiffies - rfp->rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); | |
1849 | if (i >= ARRAY_SIZE(rfp->n_launders_hist)) | |
1850 | i = ARRAY_SIZE(rfp->n_launders_hist) - 1; | |
1851 | rfp->n_launders_hist[i].n_launders++; | |
1852 | rfp->n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); | |
1853 | spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); | |
2667ccce PM |
1854 | } |
1855 | ||
ab21f608 | 1856 | // Give the scheduler a chance, even on nohz_full CPUs. |
bd1bfc51 | 1857 | static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) |
ab21f608 | 1858 | { |
90326f05 | 1859 | if (IS_ENABLED(CONFIG_PREEMPTION) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { |
bd1bfc51 PM |
1860 | // Real call_rcu() floods hit userspace, so emulate that. |
1861 | if (need_resched() || (iter & 0xfff)) | |
ab21f608 | 1862 | schedule(); |
d38e6dc6 | 1863 | return; |
ab21f608 | 1864 | } |
d38e6dc6 PM |
1865 | // No userspace emulation: CB invocation throttles call_rcu() |
1866 | cond_resched(); | |
ab21f608 PM |
1867 | } |
1868 | ||
2667ccce PM |
1869 | /* |
1870 | * Free all callbacks on the rcu_fwd_cb_head list, either because the | |
1871 | * test is over or because we hit an OOM event. | |
1872 | */ | |
6764100b | 1873 | static unsigned long rcu_torture_fwd_prog_cbfree(struct rcu_fwd *rfp) |
2667ccce PM |
1874 | { |
1875 | unsigned long flags; | |
1876 | unsigned long freed = 0; | |
1877 | struct rcu_fwd_cb *rfcp; | |
1878 | ||
1879 | for (;;) { | |
6764100b PM |
1880 | spin_lock_irqsave(&rfp->rcu_fwd_lock, flags); |
1881 | rfcp = rfp->rcu_fwd_cb_head; | |
140e53f2 | 1882 | if (!rfcp) { |
6764100b | 1883 | spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); |
2667ccce | 1884 | break; |
140e53f2 | 1885 | } |
6764100b PM |
1886 | rfp->rcu_fwd_cb_head = rfcp->rfc_next; |
1887 | if (!rfp->rcu_fwd_cb_head) | |
1888 | rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; | |
1889 | spin_unlock_irqrestore(&rfp->rcu_fwd_lock, flags); | |
2667ccce PM |
1890 | kfree(rfcp); |
1891 | freed++; | |
bd1bfc51 | 1892 | rcu_torture_fwd_prog_cond_resched(freed); |
79ba7ff5 PM |
1893 | if (tick_nohz_full_enabled()) { |
1894 | local_irq_save(flags); | |
1895 | rcu_momentary_dyntick_idle(); | |
1896 | local_irq_restore(flags); | |
1897 | } | |
2667ccce | 1898 | } |
2667ccce | 1899 | return freed; |
48718485 PM |
1900 | } |
1901 | ||
6b3de7a1 | 1902 | /* Carry out need_resched()/cond_resched() forward-progress testing. */ |
6b1b8325 PM |
1903 | static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp, |
1904 | int *tested, int *tested_tries) | |
1b27291b | 1905 | { |
119248be | 1906 | unsigned long cver; |
f4de46ed | 1907 | unsigned long dur; |
7c590fcc | 1908 | struct fwd_cb_state fcs; |
119248be | 1909 | unsigned long gps; |
1b27291b | 1910 | int idx; |
6b3de7a1 PM |
1911 | int sd; |
1912 | int sd4; | |
1913 | bool selfpropcb = false; | |
1914 | unsigned long stopat; | |
1915 | static DEFINE_TORTURE_RANDOM(trs); | |
1916 | ||
1917 | if (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) { | |
1918 | init_rcu_head_on_stack(&fcs.rh); | |
1919 | selfpropcb = true; | |
1920 | } | |
1921 | ||
1922 | /* Tight loop containing cond_resched(). */ | |
e8516c64 PM |
1923 | WRITE_ONCE(rcu_fwd_cb_nodelay, true); |
1924 | cur_ops->sync(); /* Later readers see above write. */ | |
6b3de7a1 PM |
1925 | if (selfpropcb) { |
1926 | WRITE_ONCE(fcs.stop, 0); | |
1927 | cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); | |
1928 | } | |
1929 | cver = READ_ONCE(rcu_torture_current_version); | |
1930 | gps = cur_ops->get_gp_seq(); | |
1931 | sd = cur_ops->stall_dur() + 1; | |
1932 | sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; | |
1933 | dur = sd4 + torture_random(&trs) % (sd - sd4); | |
6b1b8325 PM |
1934 | WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); |
1935 | stopat = rfp->rcu_fwd_startat + dur; | |
e0aff973 | 1936 | while (time_before(jiffies, stopat) && |
60013d5d | 1937 | !shutdown_time_arrived() && |
e0aff973 | 1938 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b3de7a1 PM |
1939 | idx = cur_ops->readlock(); |
1940 | udelay(10); | |
1941 | cur_ops->readunlock(idx); | |
1942 | if (!fwd_progress_need_resched || need_resched()) | |
fbbd5e35 | 1943 | cond_resched(); |
6b3de7a1 PM |
1944 | } |
1945 | (*tested_tries)++; | |
e0aff973 | 1946 | if (!time_before(jiffies, stopat) && |
60013d5d | 1947 | !shutdown_time_arrived() && |
e0aff973 | 1948 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b3de7a1 PM |
1949 | (*tested)++; |
1950 | cver = READ_ONCE(rcu_torture_current_version) - cver; | |
1951 | gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); | |
1952 | WARN_ON(!cver && gps < 2); | |
1953 | pr_alert("%s: Duration %ld cver %ld gps %ld\n", __func__, dur, cver, gps); | |
1954 | } | |
1955 | if (selfpropcb) { | |
1956 | WRITE_ONCE(fcs.stop, 1); | |
1957 | cur_ops->sync(); /* Wait for running CB to complete. */ | |
1958 | cur_ops->cb_barrier(); /* Wait for queued callbacks. */ | |
1959 | } | |
1960 | ||
1961 | if (selfpropcb) { | |
1962 | WARN_ON(READ_ONCE(fcs.stop) != 2); | |
1963 | destroy_rcu_head_on_stack(&fcs.rh); | |
1964 | } | |
e8516c64 PM |
1965 | schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ |
1966 | WRITE_ONCE(rcu_fwd_cb_nodelay, false); | |
6b3de7a1 PM |
1967 | } |
1968 | ||
1969 | /* Carry out call_rcu() forward-progress testing. */ | |
6b1b8325 | 1970 | static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) |
6b3de7a1 PM |
1971 | { |
1972 | unsigned long cver; | |
79ba7ff5 | 1973 | unsigned long flags; |
6b3de7a1 PM |
1974 | unsigned long gps; |
1975 | int i; | |
48718485 PM |
1976 | long n_launders; |
1977 | long n_launders_cb_snap; | |
1978 | long n_launders_sa; | |
1979 | long n_max_cbs; | |
1980 | long n_max_gps; | |
1981 | struct rcu_fwd_cb *rfcp; | |
1982 | struct rcu_fwd_cb *rfcpn; | |
1b27291b | 1983 | unsigned long stopat; |
48718485 | 1984 | unsigned long stoppedat; |
6b3de7a1 | 1985 | |
2667ccce PM |
1986 | if (READ_ONCE(rcu_fwd_emergency_stop)) |
1987 | return; /* Get out of the way quickly, no GP wait! */ | |
c682db55 PM |
1988 | if (!cur_ops->call) |
1989 | return; /* Can't do call_rcu() fwd prog without ->call. */ | |
2667ccce | 1990 | |
6b3de7a1 PM |
1991 | /* Loop continuously posting RCU callbacks. */ |
1992 | WRITE_ONCE(rcu_fwd_cb_nodelay, true); | |
1993 | cur_ops->sync(); /* Later readers see above write. */ | |
6b1b8325 PM |
1994 | WRITE_ONCE(rfp->rcu_fwd_startat, jiffies); |
1995 | stopat = rfp->rcu_fwd_startat + MAX_FWD_CB_JIFFIES; | |
6b3de7a1 | 1996 | n_launders = 0; |
6b1b8325 | 1997 | rfp->n_launders_cb = 0; // Hoist initialization for multi-kthread |
6b3de7a1 PM |
1998 | n_launders_sa = 0; |
1999 | n_max_cbs = 0; | |
2000 | n_max_gps = 0; | |
6b1b8325 PM |
2001 | for (i = 0; i < ARRAY_SIZE(rfp->n_launders_hist); i++) |
2002 | rfp->n_launders_hist[i].n_launders = 0; | |
6b3de7a1 PM |
2003 | cver = READ_ONCE(rcu_torture_current_version); |
2004 | gps = cur_ops->get_gp_seq(); | |
6b1b8325 | 2005 | rfp->rcu_launder_gp_seq_start = gps; |
d38e6dc6 | 2006 | tick_dep_set_task(current, TICK_DEP_BIT_RCU); |
e0aff973 | 2007 | while (time_before(jiffies, stopat) && |
60013d5d | 2008 | !shutdown_time_arrived() && |
e0aff973 | 2009 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b1b8325 | 2010 | rfcp = READ_ONCE(rfp->rcu_fwd_cb_head); |
6b3de7a1 PM |
2011 | rfcpn = NULL; |
2012 | if (rfcp) | |
2013 | rfcpn = READ_ONCE(rfcp->rfc_next); | |
2014 | if (rfcpn) { | |
2015 | if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && | |
2016 | ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) | |
2017 | break; | |
6b1b8325 | 2018 | rfp->rcu_fwd_cb_head = rfcpn; |
6b3de7a1 PM |
2019 | n_launders++; |
2020 | n_launders_sa++; | |
2021 | } else { | |
2022 | rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); | |
2023 | if (WARN_ON_ONCE(!rfcp)) { | |
2024 | schedule_timeout_interruptible(1); | |
2025 | continue; | |
2026 | } | |
2027 | n_max_cbs++; | |
2028 | n_launders_sa = 0; | |
2029 | rfcp->rfc_gps = 0; | |
6b1b8325 | 2030 | rfcp->rfc_rfp = rfp; |
6b3de7a1 PM |
2031 | } |
2032 | cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); | |
bd1bfc51 | 2033 | rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); |
79ba7ff5 PM |
2034 | if (tick_nohz_full_enabled()) { |
2035 | local_irq_save(flags); | |
2036 | rcu_momentary_dyntick_idle(); | |
2037 | local_irq_restore(flags); | |
2038 | } | |
6b3de7a1 PM |
2039 | } |
2040 | stoppedat = jiffies; | |
6b1b8325 | 2041 | n_launders_cb_snap = READ_ONCE(rfp->n_launders_cb); |
6b3de7a1 PM |
2042 | cver = READ_ONCE(rcu_torture_current_version) - cver; |
2043 | gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); | |
2044 | cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ | |
6764100b | 2045 | (void)rcu_torture_fwd_prog_cbfree(rfp); |
2667ccce | 2046 | |
60013d5d PM |
2047 | if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && |
2048 | !shutdown_time_arrived()) { | |
6b3de7a1 PM |
2049 | WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED); |
2050 | pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n", | |
2051 | __func__, | |
6b1b8325 | 2052 | stoppedat - rfp->rcu_fwd_startat, jiffies - stoppedat, |
6b3de7a1 PM |
2053 | n_launders + n_max_cbs - n_launders_cb_snap, |
2054 | n_launders, n_launders_sa, | |
2055 | n_max_gps, n_max_cbs, cver, gps); | |
6b1b8325 | 2056 | rcu_torture_fwd_cb_hist(rfp); |
6b3de7a1 | 2057 | } |
e8516c64 | 2058 | schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ |
d38e6dc6 | 2059 | tick_dep_clear_task(current, TICK_DEP_BIT_RCU); |
e8516c64 | 2060 | WRITE_ONCE(rcu_fwd_cb_nodelay, false); |
6b3de7a1 PM |
2061 | } |
2062 | ||
e0aff973 PM |
2063 | |
2064 | /* | |
2065 | * OOM notifier, but this only prints diagnostic information for the | |
2066 | * current forward-progress test. | |
2067 | */ | |
2068 | static int rcutorture_oom_notify(struct notifier_block *self, | |
2069 | unsigned long notused, void *nfreed) | |
2070 | { | |
5155be99 | 2071 | struct rcu_fwd *rfp = rcu_fwds; |
6764100b | 2072 | |
2667ccce PM |
2073 | WARN(1, "%s invoked upon OOM during forward-progress testing.\n", |
2074 | __func__); | |
6764100b PM |
2075 | rcu_torture_fwd_cb_hist(rfp); |
2076 | rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp->rcu_fwd_startat)) / 2); | |
e0aff973 | 2077 | WRITE_ONCE(rcu_fwd_emergency_stop, true); |
2667ccce PM |
2078 | smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ |
2079 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
6764100b | 2080 | __func__, rcu_torture_fwd_prog_cbfree(rfp)); |
2667ccce PM |
2081 | rcu_barrier(); |
2082 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
6764100b | 2083 | __func__, rcu_torture_fwd_prog_cbfree(rfp)); |
2667ccce PM |
2084 | rcu_barrier(); |
2085 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
6764100b | 2086 | __func__, rcu_torture_fwd_prog_cbfree(rfp)); |
2667ccce PM |
2087 | smp_mb(); /* Frees before return to avoid redoing OOM. */ |
2088 | (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ | |
2089 | pr_info("%s returning after OOM processing.\n", __func__); | |
e0aff973 PM |
2090 | return NOTIFY_OK; |
2091 | } | |
2092 | ||
2093 | static struct notifier_block rcutorture_oom_nb = { | |
2094 | .notifier_call = rcutorture_oom_notify | |
2095 | }; | |
2096 | ||
6b3de7a1 PM |
2097 | /* Carry out grace-period forward-progress testing. */ |
2098 | static int rcu_torture_fwd_prog(void *args) | |
2099 | { | |
6b1b8325 | 2100 | struct rcu_fwd *rfp = args; |
f4de46ed | 2101 | int tested = 0; |
152f4afb | 2102 | int tested_tries = 0; |
1b27291b PM |
2103 | |
2104 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); | |
5ab7ab83 | 2105 | rcu_bind_current_to_nocb(); |
fecad509 PM |
2106 | if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) |
2107 | set_user_nice(current, MAX_NICE); | |
1b27291b PM |
2108 | do { |
2109 | schedule_timeout_interruptible(fwd_progress_holdoff * HZ); | |
e0aff973 PM |
2110 | WRITE_ONCE(rcu_fwd_emergency_stop, false); |
2111 | register_oom_notifier(&rcutorture_oom_nb); | |
43550809 PM |
2112 | if (!IS_ENABLED(CONFIG_TINY_RCU) || |
2113 | rcu_inkernel_boot_has_ended()) | |
2114 | rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); | |
2115 | if (rcu_inkernel_boot_has_ended()) | |
2116 | rcu_torture_fwd_prog_cr(rfp); | |
e0aff973 | 2117 | unregister_oom_notifier(&rcutorture_oom_nb); |
48718485 | 2118 | |
1b27291b PM |
2119 | /* Avoid slow periods, better to test when busy. */ |
2120 | stutter_wait("rcu_torture_fwd_prog"); | |
2121 | } while (!torture_must_stop()); | |
152f4afb PM |
2122 | /* Short runs might not contain a valid forward-progress attempt. */ |
2123 | WARN_ON(!tested && tested_tries >= 5); | |
f4de46ed | 2124 | pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); |
1b27291b PM |
2125 | torture_kthread_stopping("rcu_torture_fwd_prog"); |
2126 | return 0; | |
2127 | } | |
2128 | ||
2129 | /* If forward-progress checking is requested and feasible, spawn the thread. */ | |
2130 | static int __init rcu_torture_fwd_prog_init(void) | |
2131 | { | |
5155be99 | 2132 | struct rcu_fwd *rfp; |
6764100b | 2133 | |
1b27291b PM |
2134 | if (!fwd_progress) |
2135 | return 0; /* Not requested, so don't do it. */ | |
5ac7cdc2 PM |
2136 | if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || |
2137 | cur_ops == &rcu_busted_ops) { | |
1b27291b PM |
2138 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); |
2139 | return 0; | |
2140 | } | |
2141 | if (stall_cpu > 0) { | |
2142 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing"); | |
2143 | if (IS_MODULE(CONFIG_RCU_TORTURE_TESTS)) | |
2144 | return -EINVAL; /* In module, can fail back to user. */ | |
2145 | WARN_ON(1); /* Make sure rcutorture notices conflict. */ | |
2146 | return 0; | |
2147 | } | |
2148 | if (fwd_progress_holdoff <= 0) | |
2149 | fwd_progress_holdoff = 1; | |
2150 | if (fwd_progress_div <= 0) | |
2151 | fwd_progress_div = 4; | |
5155be99 PM |
2152 | rfp = kzalloc(sizeof(*rfp), GFP_KERNEL); |
2153 | if (!rfp) | |
2154 | return -ENOMEM; | |
2155 | spin_lock_init(&rfp->rcu_fwd_lock); | |
2156 | rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head; | |
6764100b | 2157 | return torture_create_kthread(rcu_torture_fwd_prog, rfp, fwd_prog_task); |
1b27291b PM |
2158 | } |
2159 | ||
fae4b54f | 2160 | /* Callback function for RCU barrier testing. */ |
b3b8a4d4 | 2161 | static void rcu_torture_barrier_cbf(struct rcu_head *rcu) |
fae4b54f PM |
2162 | { |
2163 | atomic_inc(&barrier_cbs_invoked); | |
2164 | } | |
2165 | ||
50d4b629 PM |
2166 | /* IPI handler to get callback posted on desired CPU, if online. */ |
2167 | static void rcu_torture_barrier1cb(void *rcu_void) | |
2168 | { | |
2169 | struct rcu_head *rhp = rcu_void; | |
2170 | ||
2171 | cur_ops->call(rhp, rcu_torture_barrier_cbf); | |
2172 | } | |
2173 | ||
fae4b54f PM |
2174 | /* kthread function to register callbacks used to test RCU barriers. */ |
2175 | static int rcu_torture_barrier_cbs(void *arg) | |
2176 | { | |
2177 | long myid = (long)arg; | |
c6ebcbb6 | 2178 | bool lastphase = 0; |
78e4bc34 | 2179 | bool newphase; |
fae4b54f PM |
2180 | struct rcu_head rcu; |
2181 | ||
2182 | init_rcu_head_on_stack(&rcu); | |
5ccf60f2 | 2183 | VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); |
d277d868 | 2184 | set_user_nice(current, MAX_NICE); |
fae4b54f PM |
2185 | do { |
2186 | wait_event(barrier_cbs_wq[myid], | |
78e4bc34 | 2187 | (newphase = |
6c7ed42c | 2188 | smp_load_acquire(&barrier_phase)) != lastphase || |
36970bb9 | 2189 | torture_must_stop()); |
78e4bc34 | 2190 | lastphase = newphase; |
36970bb9 | 2191 | if (torture_must_stop()) |
fae4b54f | 2192 | break; |
6c7ed42c PM |
2193 | /* |
2194 | * The above smp_load_acquire() ensures barrier_phase load | |
aab05738 | 2195 | * is ordered before the following ->call(). |
6c7ed42c | 2196 | */ |
50d4b629 PM |
2197 | if (smp_call_function_single(myid, rcu_torture_barrier1cb, |
2198 | &rcu, 1)) { | |
2199 | // IPI failed, so use direct call from current CPU. | |
2200 | cur_ops->call(&rcu, rcu_torture_barrier_cbf); | |
2201 | } | |
fae4b54f PM |
2202 | if (atomic_dec_and_test(&barrier_cbs_count)) |
2203 | wake_up(&barrier_wq); | |
36970bb9 | 2204 | } while (!torture_must_stop()); |
69c60455 PM |
2205 | if (cur_ops->cb_barrier != NULL) |
2206 | cur_ops->cb_barrier(); | |
fae4b54f | 2207 | destroy_rcu_head_on_stack(&rcu); |
7fafaac5 | 2208 | torture_kthread_stopping("rcu_torture_barrier_cbs"); |
fae4b54f PM |
2209 | return 0; |
2210 | } | |
2211 | ||
2212 | /* kthread function to drive and coordinate RCU barrier testing. */ | |
2213 | static int rcu_torture_barrier(void *arg) | |
2214 | { | |
2215 | int i; | |
2216 | ||
5ccf60f2 | 2217 | VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); |
fae4b54f PM |
2218 | do { |
2219 | atomic_set(&barrier_cbs_invoked, 0); | |
2220 | atomic_set(&barrier_cbs_count, n_barrier_cbs); | |
6c7ed42c PM |
2221 | /* Ensure barrier_phase ordered after prior assignments. */ |
2222 | smp_store_release(&barrier_phase, !barrier_phase); | |
fae4b54f PM |
2223 | for (i = 0; i < n_barrier_cbs; i++) |
2224 | wake_up(&barrier_cbs_wq[i]); | |
2225 | wait_event(barrier_wq, | |
2226 | atomic_read(&barrier_cbs_count) == 0 || | |
36970bb9 PM |
2227 | torture_must_stop()); |
2228 | if (torture_must_stop()) | |
fae4b54f PM |
2229 | break; |
2230 | n_barrier_attempts++; | |
78e4bc34 | 2231 | cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ |
fae4b54f PM |
2232 | if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { |
2233 | n_rcu_torture_barrier_error++; | |
7602de4a PM |
2234 | pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", |
2235 | atomic_read(&barrier_cbs_invoked), | |
2236 | n_barrier_cbs); | |
9470a18f PM |
2237 | WARN_ON(1); |
2238 | // Wait manually for the remaining callbacks | |
2239 | i = 0; | |
2240 | do { | |
2241 | if (WARN_ON(i++ > HZ)) | |
2242 | i = INT_MIN; | |
2243 | schedule_timeout_interruptible(1); | |
2244 | cur_ops->cb_barrier(); | |
2245 | } while (atomic_read(&barrier_cbs_invoked) != | |
2246 | n_barrier_cbs && | |
2247 | !torture_must_stop()); | |
2248 | smp_mb(); // Can't trust ordering if broken. | |
2249 | if (!torture_must_stop()) | |
2250 | pr_err("Recovered: barrier_cbs_invoked = %d\n", | |
2251 | atomic_read(&barrier_cbs_invoked)); | |
bf5b6435 JFG |
2252 | } else { |
2253 | n_barrier_successes++; | |
fae4b54f | 2254 | } |
fae4b54f | 2255 | schedule_timeout_interruptible(HZ / 10); |
36970bb9 | 2256 | } while (!torture_must_stop()); |
7fafaac5 | 2257 | torture_kthread_stopping("rcu_torture_barrier"); |
fae4b54f PM |
2258 | return 0; |
2259 | } | |
2260 | ||
2261 | /* Initialize RCU barrier testing. */ | |
2262 | static int rcu_torture_barrier_init(void) | |
2263 | { | |
2264 | int i; | |
2265 | int ret; | |
2266 | ||
d9eba768 | 2267 | if (n_barrier_cbs <= 0) |
fae4b54f PM |
2268 | return 0; |
2269 | if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { | |
2caa1e44 PM |
2270 | pr_alert("%s" TORTURE_FLAG |
2271 | " Call or barrier ops missing for %s,\n", | |
2272 | torture_type, cur_ops->name); | |
2273 | pr_alert("%s" TORTURE_FLAG | |
2274 | " RCU barrier testing omitted from run.\n", | |
2275 | torture_type); | |
fae4b54f PM |
2276 | return 0; |
2277 | } | |
2278 | atomic_set(&barrier_cbs_count, 0); | |
2279 | atomic_set(&barrier_cbs_invoked, 0); | |
2280 | barrier_cbs_tasks = | |
68a675d4 | 2281 | kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]), |
fae4b54f PM |
2282 | GFP_KERNEL); |
2283 | barrier_cbs_wq = | |
68a675d4 | 2284 | kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL); |
de5e6437 | 2285 | if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) |
fae4b54f PM |
2286 | return -ENOMEM; |
2287 | for (i = 0; i < n_barrier_cbs; i++) { | |
2288 | init_waitqueue_head(&barrier_cbs_wq[i]); | |
47cf29b9 PM |
2289 | ret = torture_create_kthread(rcu_torture_barrier_cbs, |
2290 | (void *)(long)i, | |
2291 | barrier_cbs_tasks[i]); | |
2292 | if (ret) | |
fae4b54f | 2293 | return ret; |
fae4b54f | 2294 | } |
47cf29b9 | 2295 | return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); |
fae4b54f PM |
2296 | } |
2297 | ||
2298 | /* Clean up after RCU barrier testing. */ | |
2299 | static void rcu_torture_barrier_cleanup(void) | |
2300 | { | |
2301 | int i; | |
2302 | ||
9c029b86 | 2303 | torture_stop_kthread(rcu_torture_barrier, barrier_task); |
fae4b54f | 2304 | if (barrier_cbs_tasks != NULL) { |
9c029b86 PM |
2305 | for (i = 0; i < n_barrier_cbs; i++) |
2306 | torture_stop_kthread(rcu_torture_barrier_cbs, | |
2307 | barrier_cbs_tasks[i]); | |
fae4b54f PM |
2308 | kfree(barrier_cbs_tasks); |
2309 | barrier_cbs_tasks = NULL; | |
2310 | } | |
2311 | if (barrier_cbs_wq != NULL) { | |
2312 | kfree(barrier_cbs_wq); | |
2313 | barrier_cbs_wq = NULL; | |
2314 | } | |
2315 | } | |
2316 | ||
4babd855 JFG |
2317 | static bool rcu_torture_can_boost(void) |
2318 | { | |
2319 | static int boost_warn_once; | |
2320 | int prio; | |
2321 | ||
2322 | if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) | |
2323 | return false; | |
2324 | ||
2325 | prio = rcu_get_gp_kthreads_prio(); | |
2326 | if (!prio) | |
2327 | return false; | |
2328 | ||
2329 | if (prio < 2) { | |
2330 | if (boost_warn_once == 1) | |
2331 | return false; | |
2332 | ||
bf5b6435 | 2333 | pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME); |
4babd855 JFG |
2334 | boost_warn_once = 1; |
2335 | return false; | |
2336 | } | |
2337 | ||
2338 | return true; | |
2339 | } | |
2340 | ||
0ffd374b | 2341 | static enum cpuhp_state rcutor_hp; |
8e8be45e | 2342 | |
a241ec65 PM |
2343 | static void |
2344 | rcu_torture_cleanup(void) | |
2345 | { | |
c116dba6 | 2346 | int firsttime; |
034777d7 | 2347 | int flags = 0; |
aebc8264 | 2348 | unsigned long gp_seq = 0; |
a241ec65 PM |
2349 | int i; |
2350 | ||
d36a7a0d | 2351 | if (torture_cleanup_begin()) { |
343e9099 PM |
2352 | if (cur_ops->cb_barrier != NULL) |
2353 | cur_ops->cb_barrier(); | |
2354 | return; | |
2355 | } | |
b813afae PM |
2356 | if (!cur_ops) { |
2357 | torture_cleanup_end(); | |
2358 | return; | |
2359 | } | |
d84f5203 | 2360 | |
f7a81b12 | 2361 | show_rcu_gp_kthreads(); |
fae4b54f | 2362 | rcu_torture_barrier_cleanup(); |
1b27291b | 2363 | torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task); |
9c029b86 | 2364 | torture_stop_kthread(rcu_torture_stall, stall_task); |
9c029b86 | 2365 | torture_stop_kthread(rcu_torture_writer, writer_task); |
a241ec65 | 2366 | |
c8e5b163 | 2367 | if (reader_tasks) { |
9c029b86 PM |
2368 | for (i = 0; i < nrealreaders; i++) |
2369 | torture_stop_kthread(rcu_torture_reader, | |
2370 | reader_tasks[i]); | |
a241ec65 | 2371 | kfree(reader_tasks); |
a241ec65 PM |
2372 | } |
2373 | rcu_torture_current = NULL; | |
2374 | ||
c8e5b163 | 2375 | if (fakewriter_tasks) { |
b772e1dd | 2376 | for (i = 0; i < nfakewriters; i++) { |
9c029b86 PM |
2377 | torture_stop_kthread(rcu_torture_fakewriter, |
2378 | fakewriter_tasks[i]); | |
b772e1dd JT |
2379 | } |
2380 | kfree(fakewriter_tasks); | |
2381 | fakewriter_tasks = NULL; | |
2382 | } | |
2383 | ||
aebc8264 PM |
2384 | rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq); |
2385 | srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq); | |
2386 | pr_alert("%s: End-test grace-period state: g%lu f%#x\n", | |
2387 | cur_ops->name, gp_seq, flags); | |
9c029b86 PM |
2388 | torture_stop_kthread(rcu_torture_stats, stats_task); |
2389 | torture_stop_kthread(rcu_torture_fqs, fqs_task); | |
4babd855 | 2390 | if (rcu_torture_can_boost()) |
0ffd374b | 2391 | cpuhp_remove_state(rcutor_hp); |
bf66f18e | 2392 | |
ca1d51ed | 2393 | /* |
62a1a945 | 2394 | * Wait for all RCU callbacks to fire, then do torture-type-specific |
ca1d51ed PM |
2395 | * cleanup operations. |
2396 | */ | |
2326974d PM |
2397 | if (cur_ops->cb_barrier != NULL) |
2398 | cur_ops->cb_barrier(); | |
ca1d51ed PM |
2399 | if (cur_ops->cleanup != NULL) |
2400 | cur_ops->cleanup(); | |
a241ec65 | 2401 | |
a241ec65 | 2402 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 2403 | |
c116dba6 PM |
2404 | if (err_segs_recorded) { |
2405 | pr_alert("Failure/close-call rcutorture reader segments:\n"); | |
2406 | if (rt_read_nsegs == 0) | |
2407 | pr_alert("\t: No segments recorded!!!\n"); | |
2408 | firsttime = 1; | |
2409 | for (i = 0; i < rt_read_nsegs; i++) { | |
2410 | pr_alert("\t%d: %#x ", i, err_segs[i].rt_readstate); | |
2411 | if (err_segs[i].rt_delay_jiffies != 0) { | |
2412 | pr_cont("%s%ldjiffies", firsttime ? "" : "+", | |
2413 | err_segs[i].rt_delay_jiffies); | |
2414 | firsttime = 0; | |
2415 | } | |
2416 | if (err_segs[i].rt_delay_ms != 0) { | |
2417 | pr_cont("%s%ldms", firsttime ? "" : "+", | |
2418 | err_segs[i].rt_delay_ms); | |
2419 | firsttime = 0; | |
2420 | } | |
2421 | if (err_segs[i].rt_delay_us != 0) { | |
2422 | pr_cont("%s%ldus", firsttime ? "" : "+", | |
2423 | err_segs[i].rt_delay_us); | |
2424 | firsttime = 0; | |
2425 | } | |
2426 | pr_cont("%s\n", | |
2427 | err_segs[i].rt_preempted ? "preempted" : ""); | |
2428 | ||
2429 | } | |
2430 | } | |
fae4b54f | 2431 | if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) |
8e8be45e | 2432 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); |
2e9e8081 | 2433 | else if (torture_onoff_failures()) |
091541bb PM |
2434 | rcu_torture_print_module_parms(cur_ops, |
2435 | "End of test: RCU_HOTPLUG"); | |
95c38322 | 2436 | else |
8e8be45e | 2437 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); |
d36a7a0d | 2438 | torture_cleanup_end(); |
a241ec65 PM |
2439 | } |
2440 | ||
d2818df1 PM |
2441 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD |
2442 | static void rcu_torture_leak_cb(struct rcu_head *rhp) | |
2443 | { | |
2444 | } | |
2445 | ||
2446 | static void rcu_torture_err_cb(struct rcu_head *rhp) | |
2447 | { | |
2448 | /* | |
2449 | * This -might- happen due to race conditions, but is unlikely. | |
2450 | * The scenario that leads to this happening is that the | |
2451 | * first of the pair of duplicate callbacks is queued, | |
2452 | * someone else starts a grace period that includes that | |
2453 | * callback, then the second of the pair must wait for the | |
2454 | * next grace period. Unlikely, but can happen. If it | |
2455 | * does happen, the debug-objects subsystem won't have splatted. | |
2456 | */ | |
e0d31a34 | 2457 | pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME); |
d2818df1 PM |
2458 | } |
2459 | #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
2460 | ||
2461 | /* | |
2462 | * Verify that double-free causes debug-objects to complain, but only | |
2463 | * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test | |
2464 | * cannot be carried out. | |
2465 | */ | |
2466 | static void rcu_test_debug_objects(void) | |
2467 | { | |
2468 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD | |
2469 | struct rcu_head rh1; | |
2470 | struct rcu_head rh2; | |
2471 | ||
2472 | init_rcu_head_on_stack(&rh1); | |
2473 | init_rcu_head_on_stack(&rh2); | |
e0d31a34 | 2474 | pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME); |
d2818df1 PM |
2475 | |
2476 | /* Try to queue the rh2 pair of callbacks for the same grace period. */ | |
2477 | preempt_disable(); /* Prevent preemption from interrupting test. */ | |
2478 | rcu_read_lock(); /* Make it impossible to finish a grace period. */ | |
2479 | call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ | |
2480 | local_irq_disable(); /* Make it harder to start a new grace period. */ | |
2481 | call_rcu(&rh2, rcu_torture_leak_cb); | |
2482 | call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ | |
2483 | local_irq_enable(); | |
2484 | rcu_read_unlock(); | |
2485 | preempt_enable(); | |
2486 | ||
2487 | /* Wait for them all to get done so we can safely return. */ | |
2488 | rcu_barrier(); | |
e0d31a34 | 2489 | pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME); |
d2818df1 PM |
2490 | destroy_rcu_head_on_stack(&rh1); |
2491 | destroy_rcu_head_on_stack(&rh2); | |
2492 | #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
e0d31a34 | 2493 | pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME); |
d2818df1 PM |
2494 | #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ |
2495 | } | |
2496 | ||
3a6cb58f PM |
2497 | static void rcutorture_sync(void) |
2498 | { | |
2499 | static unsigned long n; | |
2500 | ||
2501 | if (cur_ops->sync && !(++n & 0xfff)) | |
2502 | cur_ops->sync(); | |
2503 | } | |
2504 | ||
6f8bc500 | 2505 | static int __init |
a241ec65 PM |
2506 | rcu_torture_init(void) |
2507 | { | |
c04dd09b | 2508 | long i; |
a241ec65 PM |
2509 | int cpu; |
2510 | int firsterr = 0; | |
2ec1f2d9 | 2511 | static struct rcu_torture_ops *torture_ops[] = { |
c770c82a | 2512 | &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, |
c1a76c0b PM |
2513 | &busted_srcud_ops, &tasks_ops, &tasks_rude_ops, |
2514 | &tasks_tracing_ops, &trivial_ops, | |
2ec1f2d9 | 2515 | }; |
a241ec65 | 2516 | |
a2f2577d | 2517 | if (!torture_init_begin(torture_type, verbose)) |
5228084e | 2518 | return -EBUSY; |
343e9099 | 2519 | |
a241ec65 | 2520 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 2521 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 2522 | cur_ops = torture_ops[i]; |
ade5fb81 | 2523 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 2524 | break; |
72e9bb54 | 2525 | } |
ade5fb81 | 2526 | if (i == ARRAY_SIZE(torture_ops)) { |
2caa1e44 PM |
2527 | pr_alert("rcu-torture: invalid torture type: \"%s\"\n", |
2528 | torture_type); | |
2529 | pr_alert("rcu-torture types:"); | |
cf886c44 | 2530 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) |
a7538352 JP |
2531 | pr_cont(" %s", torture_ops[i]->name); |
2532 | pr_cont("\n"); | |
e746b558 | 2533 | WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST)); |
889d487a | 2534 | firsterr = -EINVAL; |
b813afae | 2535 | cur_ops = NULL; |
889d487a | 2536 | goto unwind; |
72e9bb54 | 2537 | } |
bf66f18e | 2538 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
2caa1e44 | 2539 | pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); |
bf66f18e PM |
2540 | fqs_duration = 0; |
2541 | } | |
c8e5b163 | 2542 | if (cur_ops->init) |
889d487a | 2543 | cur_ops->init(); |
72e9bb54 | 2544 | |
64e4b43a | 2545 | if (nreaders >= 0) { |
a241ec65 | 2546 | nrealreaders = nreaders; |
64e4b43a | 2547 | } else { |
3838cc18 | 2548 | nrealreaders = num_online_cpus() - 2 - nreaders; |
64e4b43a PM |
2549 | if (nrealreaders <= 0) |
2550 | nrealreaders = 1; | |
2551 | } | |
8e8be45e | 2552 | rcu_torture_print_module_parms(cur_ops, "Start of test"); |
a241ec65 PM |
2553 | |
2554 | /* Set up the freelist. */ | |
2555 | ||
2556 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 2557 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 2558 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
2559 | list_add_tail(&rcu_tortures[i].rtort_free, |
2560 | &rcu_torture_freelist); | |
2561 | } | |
2562 | ||
2563 | /* Initialize the statistics so that each run gets its own numbers. */ | |
2564 | ||
2565 | rcu_torture_current = NULL; | |
2566 | rcu_torture_current_version = 0; | |
2567 | atomic_set(&n_rcu_torture_alloc, 0); | |
2568 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
2569 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
2570 | atomic_set(&n_rcu_torture_mberror, 0); |
2571 | atomic_set(&n_rcu_torture_error, 0); | |
fae4b54f | 2572 | n_rcu_torture_barrier_error = 0; |
8e8be45e PM |
2573 | n_rcu_torture_boost_ktrerror = 0; |
2574 | n_rcu_torture_boost_rterror = 0; | |
8e8be45e PM |
2575 | n_rcu_torture_boost_failure = 0; |
2576 | n_rcu_torture_boosts = 0; | |
a241ec65 PM |
2577 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
2578 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 2579 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
2580 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
2581 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
2582 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
2583 | } | |
2584 | } | |
c116dba6 PM |
2585 | err_segs_recorded = 0; |
2586 | rt_read_nsegs = 0; | |
a241ec65 PM |
2587 | |
2588 | /* Start up the kthreads. */ | |
2589 | ||
47cf29b9 PM |
2590 | firsterr = torture_create_kthread(rcu_torture_writer, NULL, |
2591 | writer_task); | |
2592 | if (firsterr) | |
a241ec65 | 2593 | goto unwind; |
4444d852 | 2594 | if (nfakewriters > 0) { |
68a675d4 | 2595 | fakewriter_tasks = kcalloc(nfakewriters, |
4444d852 PM |
2596 | sizeof(fakewriter_tasks[0]), |
2597 | GFP_KERNEL); | |
2598 | if (fakewriter_tasks == NULL) { | |
2599 | VERBOSE_TOROUT_ERRSTRING("out of memory"); | |
2600 | firsterr = -ENOMEM; | |
2601 | goto unwind; | |
2602 | } | |
b772e1dd JT |
2603 | } |
2604 | for (i = 0; i < nfakewriters; i++) { | |
47cf29b9 PM |
2605 | firsterr = torture_create_kthread(rcu_torture_fakewriter, |
2606 | NULL, fakewriter_tasks[i]); | |
2607 | if (firsterr) | |
b772e1dd | 2608 | goto unwind; |
b772e1dd | 2609 | } |
68a675d4 | 2610 | reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), |
a241ec65 PM |
2611 | GFP_KERNEL); |
2612 | if (reader_tasks == NULL) { | |
5ccf60f2 | 2613 | VERBOSE_TOROUT_ERRSTRING("out of memory"); |
a241ec65 PM |
2614 | firsterr = -ENOMEM; |
2615 | goto unwind; | |
2616 | } | |
2617 | for (i = 0; i < nrealreaders; i++) { | |
c04dd09b | 2618 | firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, |
47cf29b9 PM |
2619 | reader_tasks[i]); |
2620 | if (firsterr) | |
a241ec65 | 2621 | goto unwind; |
a241ec65 PM |
2622 | } |
2623 | if (stat_interval > 0) { | |
47cf29b9 PM |
2624 | firsterr = torture_create_kthread(rcu_torture_stats, NULL, |
2625 | stats_task); | |
2626 | if (firsterr) | |
a241ec65 | 2627 | goto unwind; |
a241ec65 | 2628 | } |
e8e255f7 | 2629 | if (test_no_idle_hz && shuffle_interval > 0) { |
3808dc9f PM |
2630 | firsterr = torture_shuffle_init(shuffle_interval * HZ); |
2631 | if (firsterr) | |
d84f5203 | 2632 | goto unwind; |
d84f5203 | 2633 | } |
d120f65f PM |
2634 | if (stutter < 0) |
2635 | stutter = 0; | |
2636 | if (stutter) { | |
ff3bf92d PM |
2637 | int t; |
2638 | ||
2639 | t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; | |
2640 | firsterr = torture_stutter_init(stutter * HZ, t); | |
628edaa5 | 2641 | if (firsterr) |
d120f65f | 2642 | goto unwind; |
d120f65f | 2643 | } |
bf66f18e PM |
2644 | if (fqs_duration < 0) |
2645 | fqs_duration = 0; | |
2646 | if (fqs_duration) { | |
628edaa5 | 2647 | /* Create the fqs thread */ |
d0d0606e PM |
2648 | firsterr = torture_create_kthread(rcu_torture_fqs, NULL, |
2649 | fqs_task); | |
47cf29b9 | 2650 | if (firsterr) |
bf66f18e | 2651 | goto unwind; |
bf66f18e | 2652 | } |
8e8be45e PM |
2653 | if (test_boost_interval < 1) |
2654 | test_boost_interval = 1; | |
2655 | if (test_boost_duration < 2) | |
2656 | test_boost_duration = 2; | |
4babd855 | 2657 | if (rcu_torture_can_boost()) { |
8e8be45e PM |
2658 | |
2659 | boost_starttime = jiffies + test_boost_interval * HZ; | |
0ffd374b SAS |
2660 | |
2661 | firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", | |
2662 | rcutorture_booster_init, | |
2663 | rcutorture_booster_cleanup); | |
2664 | if (firsterr < 0) | |
2665 | goto unwind; | |
2666 | rcutor_hp = firsterr; | |
8e8be45e | 2667 | } |
60013d5d | 2668 | shutdown_jiffies = jiffies + shutdown_secs * HZ; |
01025ebc PM |
2669 | firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); |
2670 | if (firsterr) | |
37e377d2 | 2671 | goto unwind; |
3a6cb58f PM |
2672 | firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, |
2673 | rcutorture_sync); | |
01025ebc | 2674 | if (firsterr) |
37e377d2 | 2675 | goto unwind; |
01025ebc | 2676 | firsterr = rcu_torture_stall_init(); |
1b27291b PM |
2677 | if (firsterr) |
2678 | goto unwind; | |
2679 | firsterr = rcu_torture_fwd_prog_init(); | |
01025ebc | 2680 | if (firsterr) |
37e377d2 | 2681 | goto unwind; |
01025ebc PM |
2682 | firsterr = rcu_torture_barrier_init(); |
2683 | if (firsterr) | |
fae4b54f | 2684 | goto unwind; |
d2818df1 PM |
2685 | if (object_debug) |
2686 | rcu_test_debug_objects(); | |
b5daa8f3 | 2687 | torture_init_end(); |
a241ec65 PM |
2688 | return 0; |
2689 | ||
2690 | unwind: | |
b5daa8f3 | 2691 | torture_init_end(); |
a241ec65 PM |
2692 | rcu_torture_cleanup(); |
2693 | return firsterr; | |
2694 | } | |
2695 | ||
2696 | module_init(rcu_torture_init); | |
2697 | module_exit(rcu_torture_cleanup); |