1 // SPDX-License-Identifier: GPL-2.0+
3 // Torture test for smp_call_function() and friends.
5 // Copyright (C) Facebook, 2020.
7 // Author: Paul E. McKenney <paulmck@kernel.org>
9 #define pr_fmt(fmt) fmt
11 #include <linux/atomic.h>
12 #include <linux/bitops.h>
13 #include <linux/completion.h>
14 #include <linux/cpu.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/kthread.h>
20 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/notifier.h>
25 #include <linux/percpu.h>
26 #include <linux/rcupdate.h>
27 #include <linux/rcupdate_trace.h>
28 #include <linux/reboot.h>
29 #include <linux/sched.h>
30 #include <linux/spinlock.h>
31 #include <linux/smp.h>
32 #include <linux/stat.h>
33 #include <linux/srcu.h>
34 #include <linux/slab.h>
35 #include <linux/torture.h>
36 #include <linux/types.h>
38 #define SCFTORT_STRING "scftorture"
39 #define SCFTORT_FLAG SCFTORT_STRING ": "
41 #define VERBOSE_SCFTORTOUT(s, x...) \
42 do { if (verbose) pr_alert(SCFTORT_FLAG s "\n", ## x); } while (0)
44 #define SCFTORTOUT_ERRSTRING(s, x...) pr_alert(SCFTORT_FLAG "!!! " s "\n", ## x)
46 MODULE_LICENSE("GPL");
47 MODULE_AUTHOR("Paul E. McKenney <paulmck@kernel.org>");
49 // Wait until there are multiple CPUs before starting test.
50 torture_param(int, holdoff
, IS_BUILTIN(CONFIG_SCF_TORTURE_TEST
) ? 10 : 0,
51 "Holdoff time before test start (s)");
52 torture_param(int, longwait
, 0, "Include ridiculously long waits? (seconds)");
53 torture_param(int, nthreads
, -1, "# threads, defaults to -1 for all CPUs.");
54 torture_param(int, onoff_holdoff
, 0, "Time after boot before CPU hotplugs (s)");
55 torture_param(int, onoff_interval
, 0, "Time between CPU hotplugs (s), 0=disable");
56 torture_param(int, shutdown_secs
, 0, "Shutdown time (ms), <= zero to disable.");
57 torture_param(int, stat_interval
, 60, "Number of seconds between stats printk()s.");
58 torture_param(int, stutter
, 5, "Number of jiffies to run/halt test, 0=disable");
59 torture_param(bool, use_cpus_read_lock
, 0, "Use cpus_read_lock() to exclude CPU hotplug.");
60 torture_param(int, verbose
, 0, "Enable verbose debugging printk()s");
61 torture_param(int, weight_resched
, -1, "Testing weight for resched_cpu() operations.");
62 torture_param(int, weight_single
, -1, "Testing weight for single-CPU no-wait operations.");
63 torture_param(int, weight_single_rpc
, -1, "Testing weight for single-CPU RPC operations.");
64 torture_param(int, weight_single_wait
, -1, "Testing weight for single-CPU operations.");
65 torture_param(int, weight_many
, -1, "Testing weight for multi-CPU no-wait operations.");
66 torture_param(int, weight_many_wait
, -1, "Testing weight for multi-CPU operations.");
67 torture_param(int, weight_all
, -1, "Testing weight for all-CPU no-wait operations.");
68 torture_param(int, weight_all_wait
, -1, "Testing weight for all-CPU operations.");
70 char *torture_type
= "";
73 # define SCFTORT_SHUTDOWN 0
75 # define SCFTORT_SHUTDOWN 1
78 torture_param(bool, shutdown
, SCFTORT_SHUTDOWN
, "Shutdown at end of torture test.");
80 struct scf_statistics
{
81 struct task_struct
*task
;
85 long long n_single_ofl
;
86 long long n_single_rpc
;
87 long long n_single_rpc_ofl
;
88 long long n_single_wait
;
89 long long n_single_wait_ofl
;
91 long long n_many_wait
;
96 static struct scf_statistics
*scf_stats_p
;
97 static struct task_struct
*scf_torture_stats_task
;
98 static DEFINE_PER_CPU(long long, scf_invoked_count
);
100 // Data for random primitive selection
101 #define SCF_PRIM_RESCHED 0
102 #define SCF_PRIM_SINGLE 1
103 #define SCF_PRIM_SINGLE_RPC 2
104 #define SCF_PRIM_MANY 3
105 #define SCF_PRIM_ALL 4
106 #define SCF_NPRIMS 8 // Need wait and no-wait versions of each,
107 // except for SCF_PRIM_RESCHED and
108 // SCF_PRIM_SINGLE_RPC.
110 static char *scf_prim_name
[] = {
112 "smp_call_function_single",
113 "smp_call_function_single_rpc",
114 "smp_call_function_many",
118 struct scf_selector
{
119 unsigned long scfs_weight
;
123 static struct scf_selector scf_sel_array
[SCF_NPRIMS
];
124 static int scf_sel_array_len
;
125 static unsigned long scf_sel_totweight
;
127 // Communicate between caller and handler.
131 int scfc_cpu
; // -1 for not _single().
134 struct completion scfc_completion
;
137 // Use to wait for all threads to start.
138 static atomic_t n_started
;
139 static atomic_t n_errs
;
140 static atomic_t n_mb_in_errs
;
141 static atomic_t n_mb_out_errs
;
142 static atomic_t n_alloc_errs
;
144 static char *bangstr
= "";
146 static DEFINE_TORTURE_RANDOM_PERCPU(scf_torture_rand
);
148 extern void resched_cpu(int cpu
); // An alternative IPI vector.
150 // Print torture statistics. Caller must ensure serialization.
151 static void scf_torture_stats_print(void)
155 long long invoked_count
= 0;
156 bool isdone
= READ_ONCE(scfdone
);
157 struct scf_statistics scfs
= {};
159 for_each_possible_cpu(cpu
)
160 invoked_count
+= data_race(per_cpu(scf_invoked_count
, cpu
));
161 for (i
= 0; i
< nthreads
; i
++) {
162 scfs
.n_resched
+= scf_stats_p
[i
].n_resched
;
163 scfs
.n_single
+= scf_stats_p
[i
].n_single
;
164 scfs
.n_single_ofl
+= scf_stats_p
[i
].n_single_ofl
;
165 scfs
.n_single_rpc
+= scf_stats_p
[i
].n_single_rpc
;
166 scfs
.n_single_wait
+= scf_stats_p
[i
].n_single_wait
;
167 scfs
.n_single_wait_ofl
+= scf_stats_p
[i
].n_single_wait_ofl
;
168 scfs
.n_many
+= scf_stats_p
[i
].n_many
;
169 scfs
.n_many_wait
+= scf_stats_p
[i
].n_many_wait
;
170 scfs
.n_all
+= scf_stats_p
[i
].n_all
;
171 scfs
.n_all_wait
+= scf_stats_p
[i
].n_all_wait
;
173 if (atomic_read(&n_errs
) || atomic_read(&n_mb_in_errs
) ||
174 atomic_read(&n_mb_out_errs
) ||
175 (!IS_ENABLED(CONFIG_KASAN
) && atomic_read(&n_alloc_errs
)))
177 pr_alert("%s %sscf_invoked_count %s: %lld resched: %lld single: %lld/%lld single_ofl: %lld/%lld single_rpc: %lld single_rpc_ofl: %lld many: %lld/%lld all: %lld/%lld ",
178 SCFTORT_FLAG
, bangstr
, isdone
? "VER" : "ver", invoked_count
, scfs
.n_resched
,
179 scfs
.n_single
, scfs
.n_single_wait
, scfs
.n_single_ofl
, scfs
.n_single_wait_ofl
,
180 scfs
.n_single_rpc
, scfs
.n_single_rpc_ofl
,
181 scfs
.n_many
, scfs
.n_many_wait
, scfs
.n_all
, scfs
.n_all_wait
);
182 torture_onoff_stats();
183 pr_cont("ste: %d stnmie: %d stnmoe: %d staf: %d\n", atomic_read(&n_errs
),
184 atomic_read(&n_mb_in_errs
), atomic_read(&n_mb_out_errs
),
185 atomic_read(&n_alloc_errs
));
188 // Periodically prints torture statistics, if periodic statistics printing
189 // was specified via the stat_interval module parameter.
191 scf_torture_stats(void *arg
)
193 VERBOSE_TOROUT_STRING("scf_torture_stats task started");
195 schedule_timeout_interruptible(stat_interval
* HZ
);
196 scf_torture_stats_print();
197 torture_shutdown_absorb("scf_torture_stats");
198 } while (!torture_must_stop());
199 torture_kthread_stopping("scf_torture_stats");
203 // Add a primitive to the scf_sel_array[].
204 static void scf_sel_add(unsigned long weight
, int prim
, bool wait
)
206 struct scf_selector
*scfsp
= &scf_sel_array
[scf_sel_array_len
];
208 // If no weight, if array would overflow, if computing three-place
209 // percentages would overflow, or if the scf_prim_name[] array would
210 // overflow, don't bother. In the last three two cases, complain.
212 WARN_ON_ONCE(scf_sel_array_len
>= ARRAY_SIZE(scf_sel_array
)) ||
213 WARN_ON_ONCE(0 - 100000 * weight
<= 100000 * scf_sel_totweight
) ||
214 WARN_ON_ONCE(prim
>= ARRAY_SIZE(scf_prim_name
)))
216 scf_sel_totweight
+= weight
;
217 scfsp
->scfs_weight
= scf_sel_totweight
;
218 scfsp
->scfs_prim
= prim
;
219 scfsp
->scfs_wait
= wait
;
223 // Dump out weighting percentages for scf_prim_name[] array.
224 static void scf_sel_dump(void)
227 unsigned long oldw
= 0;
228 struct scf_selector
*scfsp
;
231 for (i
= 0; i
< scf_sel_array_len
; i
++) {
232 scfsp
= &scf_sel_array
[i
];
233 w
= (scfsp
->scfs_weight
- oldw
) * 100000 / scf_sel_totweight
;
234 pr_info("%s: %3lu.%03lu %s(%s)\n", __func__
, w
/ 1000, w
% 1000,
235 scf_prim_name
[scfsp
->scfs_prim
],
236 scfsp
->scfs_wait
? "wait" : "nowait");
237 oldw
= scfsp
->scfs_weight
;
241 // Randomly pick a primitive and wait/nowait, based on weightings.
242 static struct scf_selector
*scf_sel_rand(struct torture_random_state
*trsp
)
245 unsigned long w
= torture_random(trsp
) % (scf_sel_totweight
+ 1);
247 for (i
= 0; i
< scf_sel_array_len
; i
++)
248 if (scf_sel_array
[i
].scfs_weight
>= w
)
249 return &scf_sel_array
[i
];
251 return &scf_sel_array
[0];
254 // Update statistics and occasionally burn up mass quantities of CPU time,
255 // if told to do so via scftorture.longwait. Otherwise, occasionally burn
257 static void scf_handler(void *scfc_in
)
261 unsigned long r
= torture_random(this_cpu_ptr(&scf_torture_rand
));
262 struct scf_check
*scfcp
= scfc_in
;
265 WRITE_ONCE(scfcp
->scfc_out
, false); // For multiple receivers.
266 if (WARN_ON_ONCE(unlikely(!READ_ONCE(scfcp
->scfc_in
))))
267 atomic_inc(&n_mb_in_errs
);
269 this_cpu_inc(scf_invoked_count
);
280 udelay((r
& 0xff) + 1);
283 r
= r
% longwait
+ 1;
284 for (i
= 0; i
< r
; i
++) {
285 for (j
= 0; j
< 1000; j
++) {
291 if (unlikely(!scfcp
))
293 if (scfcp
->scfc_wait
) {
294 WRITE_ONCE(scfcp
->scfc_out
, true);
296 complete(&scfcp
->scfc_completion
);
302 // As above, but check for correct CPU.
303 static void scf_handler_1(void *scfc_in
)
305 struct scf_check
*scfcp
= scfc_in
;
307 if (likely(scfcp
) && WARN_ONCE(smp_processor_id() != scfcp
->scfc_cpu
, "%s: Wanted CPU %d got CPU %d\n", __func__
, scfcp
->scfc_cpu
, smp_processor_id())) {
313 // Randomly do an smp_call_function*() invocation.
314 static void scftorture_invoke_one(struct scf_statistics
*scfp
, struct torture_random_state
*trsp
)
316 bool allocfail
= false;
319 struct scf_check
*scfcp
= NULL
;
320 struct scf_selector
*scfsp
= scf_sel_rand(trsp
);
322 if (use_cpus_read_lock
)
326 if (scfsp
->scfs_prim
== SCF_PRIM_SINGLE
|| scfsp
->scfs_wait
) {
327 scfcp
= kmalloc(sizeof(*scfcp
), GFP_ATOMIC
);
329 WARN_ON_ONCE(!IS_ENABLED(CONFIG_KASAN
));
330 atomic_inc(&n_alloc_errs
);
333 scfcp
->scfc_cpu
= -1;
334 scfcp
->scfc_wait
= scfsp
->scfs_wait
;
335 scfcp
->scfc_out
= false;
336 scfcp
->scfc_rpc
= false;
339 switch (scfsp
->scfs_prim
) {
340 case SCF_PRIM_RESCHED
:
341 if (IS_BUILTIN(CONFIG_SCF_TORTURE_TEST
)) {
342 cpu
= torture_random(trsp
) % nr_cpu_ids
;
345 this_cpu_inc(scf_invoked_count
);
348 case SCF_PRIM_SINGLE
:
349 cpu
= torture_random(trsp
) % nr_cpu_ids
;
350 if (scfsp
->scfs_wait
)
351 scfp
->n_single_wait
++;
355 scfcp
->scfc_cpu
= cpu
;
356 barrier(); // Prevent race-reduction compiler optimizations.
357 scfcp
->scfc_in
= true;
359 ret
= smp_call_function_single(cpu
, scf_handler_1
, (void *)scfcp
, scfsp
->scfs_wait
);
361 if (scfsp
->scfs_wait
)
362 scfp
->n_single_wait_ofl
++;
364 scfp
->n_single_ofl
++;
369 case SCF_PRIM_SINGLE_RPC
:
372 cpu
= torture_random(trsp
) % nr_cpu_ids
;
373 scfp
->n_single_rpc
++;
374 scfcp
->scfc_cpu
= cpu
;
375 scfcp
->scfc_wait
= true;
376 init_completion(&scfcp
->scfc_completion
);
377 scfcp
->scfc_rpc
= true;
378 barrier(); // Prevent race-reduction compiler optimizations.
379 scfcp
->scfc_in
= true;
380 ret
= smp_call_function_single(cpu
, scf_handler_1
, (void *)scfcp
, 0);
382 if (use_cpus_read_lock
)
386 wait_for_completion(&scfcp
->scfc_completion
);
387 if (use_cpus_read_lock
)
392 scfp
->n_single_rpc_ofl
++;
398 if (scfsp
->scfs_wait
)
403 barrier(); // Prevent race-reduction compiler optimizations.
404 scfcp
->scfc_in
= true;
406 smp_call_function_many(cpu_online_mask
, scf_handler
, scfcp
, scfsp
->scfs_wait
);
409 if (scfsp
->scfs_wait
)
414 barrier(); // Prevent race-reduction compiler optimizations.
415 scfcp
->scfc_in
= true;
417 smp_call_function(scf_handler
, scfcp
, scfsp
->scfs_wait
);
422 scfcp
->scfc_out
= true;
424 if (scfcp
&& scfsp
->scfs_wait
) {
425 if (WARN_ON_ONCE((num_online_cpus() > 1 || scfsp
->scfs_prim
== SCF_PRIM_SINGLE
) &&
427 pr_warn("%s: Memory-ordering failure, scfs_prim: %d.\n", __func__
, scfsp
->scfs_prim
);
428 atomic_inc(&n_mb_out_errs
); // Leak rather than trash!
432 barrier(); // Prevent race-reduction compiler optimizations.
434 if (use_cpus_read_lock
)
439 schedule_timeout_idle((1 + longwait
) * HZ
); // Let no-wait handlers complete.
440 else if (!(torture_random(trsp
) & 0xfff))
441 schedule_timeout_uninterruptible(1);
444 // SCF test kthread. Repeatedly does calls to members of the
445 // smp_call_function() family of functions.
446 static int scftorture_invoker(void *arg
)
450 DEFINE_TORTURE_RANDOM(rand
);
451 struct scf_statistics
*scfp
= (struct scf_statistics
*)arg
;
452 bool was_offline
= false;
454 VERBOSE_SCFTORTOUT("scftorture_invoker %d: task started", scfp
->cpu
);
455 cpu
= scfp
->cpu
% nr_cpu_ids
;
456 WARN_ON_ONCE(set_cpus_allowed_ptr(current
, cpumask_of(cpu
)));
457 set_user_nice(current
, MAX_NICE
);
459 schedule_timeout_interruptible(holdoff
* HZ
);
461 VERBOSE_SCFTORTOUT("scftorture_invoker %d: Waiting for all SCF torturers from cpu %d", scfp
->cpu
, raw_smp_processor_id());
463 // Make sure that the CPU is affinitized appropriately during testing.
464 curcpu
= raw_smp_processor_id();
465 WARN_ONCE(curcpu
!= scfp
->cpu
% nr_cpu_ids
,
466 "%s: Wanted CPU %d, running on %d, nr_cpu_ids = %d\n",
467 __func__
, scfp
->cpu
, curcpu
, nr_cpu_ids
);
469 if (!atomic_dec_return(&n_started
))
470 while (atomic_read_acquire(&n_started
)) {
471 if (torture_must_stop()) {
472 VERBOSE_SCFTORTOUT("scftorture_invoker %d ended before starting", scfp
->cpu
);
475 schedule_timeout_uninterruptible(1);
478 VERBOSE_SCFTORTOUT("scftorture_invoker %d started", scfp
->cpu
);
481 scftorture_invoke_one(scfp
, &rand
);
482 while (cpu_is_offline(cpu
) && !torture_must_stop()) {
483 schedule_timeout_interruptible(HZ
/ 5);
487 set_cpus_allowed_ptr(current
, cpumask_of(cpu
));
491 stutter_wait("scftorture_invoker");
492 } while (!torture_must_stop());
494 VERBOSE_SCFTORTOUT("scftorture_invoker %d ended", scfp
->cpu
);
496 torture_kthread_stopping("scftorture_invoker");
501 scftorture_print_module_parms(const char *tag
)
503 pr_alert(SCFTORT_FLAG
504 "--- %s: verbose=%d holdoff=%d longwait=%d nthreads=%d onoff_holdoff=%d onoff_interval=%d shutdown_secs=%d stat_interval=%d stutter=%d use_cpus_read_lock=%d, weight_resched=%d, weight_single=%d, weight_single_rpc=%d, weight_single_wait=%d, weight_many=%d, weight_many_wait=%d, weight_all=%d, weight_all_wait=%d\n", tag
,
505 verbose
, holdoff
, longwait
, nthreads
, onoff_holdoff
, onoff_interval
, shutdown
, stat_interval
, stutter
, use_cpus_read_lock
, weight_resched
, weight_single
, weight_single_rpc
, weight_single_wait
, weight_many
, weight_many_wait
, weight_all
, weight_all_wait
);
508 static void scf_cleanup_handler(void *unused
)
512 static void scf_torture_cleanup(void)
516 if (torture_cleanup_begin())
519 WRITE_ONCE(scfdone
, true);
520 if (nthreads
&& scf_stats_p
)
521 for (i
= 0; i
< nthreads
; i
++)
522 torture_stop_kthread("scftorture_invoker", scf_stats_p
[i
].task
);
525 smp_call_function(scf_cleanup_handler
, NULL
, 0);
526 torture_stop_kthread(scf_torture_stats
, scf_torture_stats_task
);
527 scf_torture_stats_print(); // -After- the stats thread is stopped!
528 kfree(scf_stats_p
); // -After- the last stats print has completed!
531 if (atomic_read(&n_errs
) || atomic_read(&n_mb_in_errs
) || atomic_read(&n_mb_out_errs
))
532 scftorture_print_module_parms("End of test: FAILURE");
533 else if (torture_onoff_failures())
534 scftorture_print_module_parms("End of test: LOCK_HOTPLUG");
536 scftorture_print_module_parms("End of test: SUCCESS");
539 torture_cleanup_end();
542 static int __init
scf_torture_init(void)
546 unsigned long weight_resched1
= weight_resched
;
547 unsigned long weight_single1
= weight_single
;
548 unsigned long weight_single_rpc1
= weight_single_rpc
;
549 unsigned long weight_single_wait1
= weight_single_wait
;
550 unsigned long weight_many1
= weight_many
;
551 unsigned long weight_many_wait1
= weight_many_wait
;
552 unsigned long weight_all1
= weight_all
;
553 unsigned long weight_all_wait1
= weight_all_wait
;
555 if (!torture_init_begin(SCFTORT_STRING
, verbose
))
558 scftorture_print_module_parms("Start of test");
560 if (weight_resched
<= 0 &&
561 weight_single
<= 0 && weight_single_rpc
<= 0 && weight_single_wait
<= 0 &&
562 weight_many
<= 0 && weight_many_wait
<= 0 &&
563 weight_all
<= 0 && weight_all_wait
<= 0) {
564 weight_resched1
= weight_resched
== 0 ? 0 : 2 * nr_cpu_ids
;
565 weight_single1
= weight_single
== 0 ? 0 : 2 * nr_cpu_ids
;
566 weight_single_rpc1
= weight_single_rpc
== 0 ? 0 : 2 * nr_cpu_ids
;
567 weight_single_wait1
= weight_single_wait
== 0 ? 0 : 2 * nr_cpu_ids
;
568 weight_many1
= weight_many
== 0 ? 0 : 2;
569 weight_many_wait1
= weight_many_wait
== 0 ? 0 : 2;
570 weight_all1
= weight_all
== 0 ? 0 : 1;
571 weight_all_wait1
= weight_all_wait
== 0 ? 0 : 1;
573 if (weight_resched
== -1)
575 if (weight_single
== -1)
577 if (weight_single_rpc
== -1)
578 weight_single_rpc1
= 0;
579 if (weight_single_wait
== -1)
580 weight_single_wait1
= 0;
581 if (weight_many
== -1)
583 if (weight_many_wait
== -1)
584 weight_many_wait1
= 0;
585 if (weight_all
== -1)
587 if (weight_all_wait
== -1)
588 weight_all_wait1
= 0;
590 if (weight_resched1
== 0 && weight_single1
== 0 && weight_single_rpc1
== 0 &&
591 weight_single_wait1
== 0 && weight_many1
== 0 && weight_many_wait1
== 0 &&
592 weight_all1
== 0 && weight_all_wait1
== 0) {
593 SCFTORTOUT_ERRSTRING("all zero weights makes no sense");
597 if (IS_BUILTIN(CONFIG_SCF_TORTURE_TEST
))
598 scf_sel_add(weight_resched1
, SCF_PRIM_RESCHED
, false);
599 else if (weight_resched1
)
600 SCFTORTOUT_ERRSTRING("built as module, weight_resched ignored");
601 scf_sel_add(weight_single1
, SCF_PRIM_SINGLE
, false);
602 scf_sel_add(weight_single_rpc1
, SCF_PRIM_SINGLE_RPC
, true);
603 scf_sel_add(weight_single_wait1
, SCF_PRIM_SINGLE
, true);
604 scf_sel_add(weight_many1
, SCF_PRIM_MANY
, false);
605 scf_sel_add(weight_many_wait1
, SCF_PRIM_MANY
, true);
606 scf_sel_add(weight_all1
, SCF_PRIM_ALL
, false);
607 scf_sel_add(weight_all_wait1
, SCF_PRIM_ALL
, true);
610 if (onoff_interval
> 0) {
611 firsterr
= torture_onoff_init(onoff_holdoff
* HZ
, onoff_interval
, NULL
);
612 if (torture_init_error(firsterr
))
615 if (shutdown_secs
> 0) {
616 firsterr
= torture_shutdown_init(shutdown_secs
, scf_torture_cleanup
);
617 if (torture_init_error(firsterr
))
621 firsterr
= torture_stutter_init(stutter
, stutter
);
622 if (torture_init_error(firsterr
))
626 // Worker tasks invoking smp_call_function().
628 nthreads
= num_online_cpus();
629 scf_stats_p
= kcalloc(nthreads
, sizeof(scf_stats_p
[0]), GFP_KERNEL
);
631 SCFTORTOUT_ERRSTRING("out of memory");
636 VERBOSE_SCFTORTOUT("Starting %d smp_call_function() threads", nthreads
);
638 atomic_set(&n_started
, nthreads
);
639 for (i
= 0; i
< nthreads
; i
++) {
640 scf_stats_p
[i
].cpu
= i
;
641 firsterr
= torture_create_kthread(scftorture_invoker
, (void *)&scf_stats_p
[i
],
642 scf_stats_p
[i
].task
);
643 if (torture_init_error(firsterr
))
646 if (stat_interval
> 0) {
647 firsterr
= torture_create_kthread(scf_torture_stats
, NULL
, scf_torture_stats_task
);
648 if (torture_init_error(firsterr
))
657 scf_torture_cleanup();
659 WARN_ON(!IS_MODULE(CONFIG_SCF_TORTURE_TEST
));
665 module_init(scf_torture_init
);
666 module_exit(scf_torture_cleanup
);