sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional

All the big Linux distros enable CONFIG_SCHED_DEBUG, because
the various features it provides help not just with kernel
development, but with system administration and user-space
software development as well.

Reflect this reality and enable this functionality
unconditionally.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org

diff --git a/fs/proc/base.c b/fs/proc/base.c
index cd89e956c322440f35ed75187416f4b247b07f96..61526420d0eeb62fb8406069ee45e9e2fcabaa4e 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1489,7 +1489,6 @@ static const struct file_operations proc_fail_nth_operations = {
 #endif
 
 
-#ifdef CONFIG_SCHED_DEBUG
 /*
  * Print out various scheduling related per-task fields:
  */
@@ -1539,8 +1538,6 @@ static const struct file_operations proc_pid_sched_operations = {
        .release        = single_release,
 };
 
-#endif
-
 #ifdef CONFIG_SCHED_AUTOGROUP
 /*
  * Print out autogroup related information:
@@ -3331,9 +3328,7 @@ static const struct pid_entry tgid_base_stuff[] = {
        ONE("status",     S_IRUGO, proc_pid_status),
        ONE("personality", S_IRUSR, proc_pid_personality),
        ONE("limits",     S_IRUGO, proc_pid_limits),
-#ifdef CONFIG_SCHED_DEBUG
        REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
-#endif
 #ifdef CONFIG_SCHED_AUTOGROUP
        REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
 #endif
@@ -3682,9 +3677,7 @@ static const struct pid_entry tid_base_stuff[] = {
        ONE("status",    S_IRUGO, proc_pid_status),
        ONE("personality", S_IRUSR, proc_pid_personality),
        ONE("limits",    S_IRUGO, proc_pid_limits),
-#ifdef CONFIG_SCHED_DEBUG
        REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
-#endif
        NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
                         &proc_tid_comm_inode_operations,
                         &proc_pid_set_comm_operations, {}),

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 78318d49276dc049bcd79e381b61d3aade49b648..65efc0f5ea2e34c11395f7a5811f9e13d26a808a 100644 (file)
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -240,9 +240,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
        struct em_perf_state *ps;
        int i;
 
-#ifdef CONFIG_SCHED_DEBUG
        WARN_ONCE(!rcu_read_lock_held(), "EM: rcu read lock needed\n");
-#endif
 
        if (!sum_util)
                return 0;

diff --git a/include/linux/sched/debug.h b/include/linux/sched/debug.h
index b5035afa23966b17af674897808240662684f499..35ed4577a6cca0b9919245d5b24d3229ad33312d 100644 (file)
--- a/include/linux/sched/debug.h
+++ b/include/linux/sched/debug.h
@@ -35,12 +35,10 @@ extern void show_stack(struct task_struct *task, unsigned long *sp,
 
 extern void sched_show_task(struct task_struct *p);
 
-#ifdef CONFIG_SCHED_DEBUG
 struct seq_file;
 extern void proc_sched_show_task(struct task_struct *p,
                                 struct pid_namespace *ns, struct seq_file *m);
 extern void proc_sched_set_task(struct task_struct *p);
-#endif
 
 /* Attach to any functions which should be ignored in wchan output. */
 #define __sched                __section(".sched.text")

diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 51f7b8169515d4ee830a8f5fe2f501da2653afa7..7b4301b7235f6df3ced1964e0de9afd9e867b3d0 100644 (file)
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -25,16 +25,12 @@ enum {
 };
 #undef SD_FLAG
 
-#ifdef CONFIG_SCHED_DEBUG
-
 struct sd_flag_debug {
        unsigned int meta_flags;
        char *name;
 };
 extern const struct sd_flag_debug sd_flag_debug[];
 
-#endif
-
 #ifdef CONFIG_SCHED_SMT
 static inline int cpu_smt_flags(void)
 {

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 9ea4c404bd4ef3efab26e0d1f135a329d21e69de..bfd97cce40a1a073104a58166ddec3a338da609a 100644 (file)
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -193,9 +193,7 @@ static inline long __trace_sched_switch_state(bool preempt,
 {
        unsigned int state;
 
-#ifdef CONFIG_SCHED_DEBUG
        BUG_ON(p != current);
-#endif /* CONFIG_SCHED_DEBUG */
 
        /*
         * Preemption ignores task state, therefore preempted tasks are always

diff --git a/kernel/sched/build_utility.c b/kernel/sched/build_utility.c
index 80a3df49ab478420a8827f62a0bdf3374479082e..bf9d8db94b7000ec296e9273965c19cba2f987aa 100644 (file)
--- a/kernel/sched/build_utility.c
+++ b/kernel/sched/build_utility.c
@@ -68,9 +68,7 @@
 # include "cpufreq_schedutil.c"
 #endif
 
-#ifdef CONFIG_SCHED_DEBUG
-# include "debug.c"
-#endif
+#include "debug.c"
 
 #ifdef CONFIG_SCHEDSTATS
 # include "stats.c"

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3589abc2f707032768acad475173a80ae3afce3b..9a4109f593ab6bf0b55fcd4e7cb6b0dcc41c1d21 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -118,7 +118,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(sched_compute_energy_tp);
 
 DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
-#ifdef CONFIG_SCHED_DEBUG
 /*
  * Debugging: various feature bits
  *
@@ -142,7 +141,6 @@ __read_mostly unsigned int sysctl_sched_features =
  */
 __read_mostly int sysctl_resched_latency_warn_ms = 100;
 __read_mostly int sysctl_resched_latency_warn_once = 1;
-#endif /* CONFIG_SCHED_DEBUG */
 
 /*
  * Number of tasks to iterate in a single balance run.
@@ -799,11 +797,10 @@ void update_rq_clock(struct rq *rq)
        if (rq->clock_update_flags & RQCF_ACT_SKIP)
                return;
 
-#ifdef CONFIG_SCHED_DEBUG
        if (sched_feat(WARN_DOUBLE_CLOCK))
                WARN_ON_ONCE(rq->clock_update_flags & RQCF_UPDATED);
        rq->clock_update_flags |= RQCF_UPDATED;
-#endif
+
        clock = sched_clock_cpu(cpu_of(rq));
        scx_rq_clock_update(rq, clock);
 
@@ -3291,7 +3288,6 @@ void relax_compatible_cpus_allowed_ptr(struct task_struct *p)
 
 void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
-#ifdef CONFIG_SCHED_DEBUG
        unsigned int state = READ_ONCE(p->__state);
 
        /*
@@ -3329,7 +3325,6 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
        WARN_ON_ONCE(!cpu_online(new_cpu));
 
        WARN_ON_ONCE(is_migration_disabled(p));
-#endif
 
        trace_sched_migrate_task(p, new_cpu);
 
@@ -5577,7 +5572,6 @@ unsigned long long task_sched_runtime(struct task_struct *p)
        return ns;
 }
 
-#ifdef CONFIG_SCHED_DEBUG
 static u64 cpu_resched_latency(struct rq *rq)
 {
        int latency_warn_ms = READ_ONCE(sysctl_resched_latency_warn_ms);
@@ -5622,9 +5616,6 @@ static int __init setup_resched_latency_warn_ms(char *str)
        return 1;
 }
 __setup("resched_latency_warn_ms=", setup_resched_latency_warn_ms);
-#else
-static inline u64 cpu_resched_latency(struct rq *rq) { return 0; }
-#endif /* CONFIG_SCHED_DEBUG */
 
 /*
  * This function gets called by the timer code, with HZ frequency.
@@ -6718,9 +6709,7 @@ static void __sched notrace __schedule(int sched_mode)
 picked:
        clear_tsk_need_resched(prev);
        clear_preempt_need_resched();
-#ifdef CONFIG_SCHED_DEBUG
        rq->last_seen_need_resched_ns = 0;
-#endif
 
        if (likely(prev != next)) {
                rq->nr_switches++;
@@ -7094,7 +7083,7 @@ asmlinkage __visible void __sched preempt_schedule_irq(void)
 int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags,
                          void *key)
 {
-       WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~(WF_SYNC|WF_CURRENT_CPU));
+       WARN_ON_ONCE(wake_flags & ~(WF_SYNC|WF_CURRENT_CPU));
        return try_to_wake_up(curr->private, mode, wake_flags);
 }
 EXPORT_SYMBOL(default_wake_function);
@@ -7811,10 +7800,9 @@ void show_state_filter(unsigned int state_filter)
                        sched_show_task(p);
        }
 
-#ifdef CONFIG_SCHED_DEBUG
        if (!state_filter)
                sysrq_sched_debug_show();
-#endif
+
        rcu_read_unlock();
        /*
         * Only show locks if all tasks are dumped:

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d4f7cbf16ec5ee7ba0fb490b62e9ee03294fc126..03a33b59776851eec8d73d05903a7a81c6f24b90 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -3574,9 +3574,7 @@ void dl_bw_free(int cpu, u64 dl_bw)
 }
 #endif
 
-#ifdef CONFIG_SCHED_DEBUG
 void print_dl_stats(struct seq_file *m, int cpu)
 {
        print_dl_rq(m, cpu, &cpu_rq(cpu)->dl);
 }
-#endif /* CONFIG_SCHED_DEBUG */

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 35ee8d9d78d526ef4b8fb0c188bc3cf86584c3ac..a0c4cd26ee0782a3714694bbe185e4befc56b62a 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -983,7 +983,6 @@ found:
        return best;
 }
 
-#ifdef CONFIG_SCHED_DEBUG
 struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
        struct rb_node *last = rb_last(&cfs_rq->tasks_timeline.rb_root);
@@ -1010,7 +1009,6 @@ int sched_update_scaling(void)
        return 0;
 }
 #endif
-#endif
 
 static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se);
 
@@ -13668,7 +13666,6 @@ DEFINE_SCHED_CLASS(fair) = {
 #endif
 };
 
-#ifdef CONFIG_SCHED_DEBUG
 void print_cfs_stats(struct seq_file *m, int cpu)
 {
        struct cfs_rq *cfs_rq, *pos;
@@ -13702,7 +13699,6 @@ void show_numa_stats(struct task_struct *p, struct seq_file *m)
        rcu_read_unlock();
 }
 #endif /* CONFIG_NUMA_BALANCING */
-#endif /* CONFIG_SCHED_DEBUG */
 
 __init void init_sched_fair_class(void)
 {

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8b8d2c10294a6c375665de99b615d7df534754dc..a4774155ae121ccbdf37814d7084036b1a076c84 100644 (file)
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -169,9 +169,8 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
 
 static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
 {
-#ifdef CONFIG_SCHED_DEBUG
        WARN_ON_ONCE(!rt_entity_is_task(rt_se));
-#endif
+
        return container_of(rt_se, struct task_struct, rt);
 }
 
@@ -2969,7 +2968,6 @@ static int sched_rr_handler(const struct ctl_table *table, int write, void *buff
 }
 #endif /* CONFIG_SYSCTL */
 
-#ifdef CONFIG_SCHED_DEBUG
 void print_rt_stats(struct seq_file *m, int cpu)
 {
        rt_rq_iter_t iter;
@@ -2980,4 +2978,3 @@ void print_rt_stats(struct seq_file *m, int cpu)
                print_rt_rq(m, cpu, rt_rq);
        rcu_read_unlock();
 }
-#endif /* CONFIG_SCHED_DEBUG */

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index d8e404028cffe91ea392ba223155903a10f97c8b..47972f34ea70144d40446ee7bb6ca922608eed5c 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1174,10 +1174,8 @@ struct rq {
 
        atomic_t                nr_iowait;
 
-#ifdef CONFIG_SCHED_DEBUG
        u64 last_seen_need_resched_ns;
        int ticks_without_resched;
-#endif
 
 #ifdef CONFIG_MEMBARRIER
        int membarrier_state;
@@ -1706,14 +1704,12 @@ static inline void rq_clock_stop_loop_update(struct rq *rq)
 struct rq_flags {
        unsigned long flags;
        struct pin_cookie cookie;
-#ifdef CONFIG_SCHED_DEBUG
        /*
         * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
         * current pin context is stashed here in case it needs to be
         * restored in rq_repin_lock().
         */
        unsigned int clock_update_flags;
-#endif
 };
 
 extern struct balance_callback balance_push_callback;
@@ -1764,21 +1760,18 @@ static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
 {
        rf->cookie = lockdep_pin_lock(__rq_lockp(rq));
 
-#ifdef CONFIG_SCHED_DEBUG
        rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
        rf->clock_update_flags = 0;
-# ifdef CONFIG_SMP
+#ifdef CONFIG_SMP
        WARN_ON_ONCE(rq->balance_callback && rq->balance_callback != &balance_push_callback);
-# endif
 #endif
 }
 
 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
 {
-#ifdef CONFIG_SCHED_DEBUG
        if (rq->clock_update_flags > RQCF_ACT_SKIP)
                rf->clock_update_flags = RQCF_UPDATED;
-#endif
+
        scx_rq_clock_invalidate(rq);
        lockdep_unpin_lock(__rq_lockp(rq), rf->cookie);
 }
@@ -1787,12 +1780,10 @@ static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
 {
        lockdep_repin_lock(__rq_lockp(rq), rf->cookie);
 
-#ifdef CONFIG_SCHED_DEBUG
        /*
         * Restore the value we stashed in @rf for this pin context.
         */
        rq->clock_update_flags |= rf->clock_update_flags;
-#endif
 }
 
 extern
@@ -2066,9 +2057,7 @@ struct sched_group_capacity {
        unsigned long           next_update;
        int                     imbalance;              /* XXX unrelated to capacity but shared group state */
 
-#ifdef CONFIG_SCHED_DEBUG
        int                     id;
-#endif
 
        unsigned long           cpumask[];              /* Balance mask */
 };
@@ -2108,13 +2097,8 @@ static inline struct cpumask *group_balance_mask(struct sched_group *sg)
 
 extern int group_balance_cpu(struct sched_group *sg);
 
-#ifdef CONFIG_SCHED_DEBUG
 extern void update_sched_domain_debugfs(void);
 extern void dirty_sched_domain_sysctl(int cpu);
-#else
-static inline void update_sched_domain_debugfs(void) { }
-static inline void dirty_sched_domain_sysctl(int cpu) { }
-#endif
 
 extern int sched_update_scaling(void);
 
@@ -2207,8 +2191,6 @@ enum {
 
 #undef SCHED_FEAT
 
-#ifdef CONFIG_SCHED_DEBUG
-
 /*
  * To support run-time toggling of sched features, all the translation units
  * (but core.c) reference the sysctl_sched_features defined in core.c.
@@ -2235,24 +2217,6 @@ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
 
 #endif /* !CONFIG_JUMP_LABEL */
 
-#else /* !SCHED_DEBUG: */
-
-/*
- * Each translation unit has its own copy of sysctl_sched_features to allow
- * constants propagation at compile time and compiler optimization based on
- * features default.
- */
-#define SCHED_FEAT(name, enabled)      \
-       (1UL << __SCHED_FEAT_##name) * enabled |
-static __read_mostly __maybe_unused unsigned int sysctl_sched_features =
-#include "features.h"
-       0;
-#undef SCHED_FEAT
-
-#define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
-
-#endif /* !SCHED_DEBUG */
-
 extern struct static_key_false sched_numa_balancing;
 extern struct static_key_false sched_schedstats;
 
@@ -2837,7 +2801,6 @@ extern __read_mostly unsigned int sysctl_sched_migration_cost;
 
 extern unsigned int sysctl_sched_base_slice;
 
-#ifdef CONFIG_SCHED_DEBUG
 extern int sysctl_resched_latency_warn_ms;
 extern int sysctl_resched_latency_warn_once;
 
@@ -2848,7 +2811,6 @@ extern unsigned int sysctl_numa_balancing_scan_period_min;
 extern unsigned int sysctl_numa_balancing_scan_period_max;
 extern unsigned int sysctl_numa_balancing_scan_size;
 extern unsigned int sysctl_numa_balancing_hot_threshold;
-#endif
 
 #ifdef CONFIG_SCHED_HRTICK
 
@@ -2921,7 +2883,6 @@ unsigned long arch_scale_freq_capacity(int cpu)
 }
 #endif
 
-#ifdef CONFIG_SCHED_DEBUG
 /*
  * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to
  * acquire rq lock instead of rq_lock(). So at the end of these two functions
@@ -2936,9 +2897,6 @@ static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2)
        rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
 #endif
 }
-#else
-static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) { }
-#endif
 
 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...)                           \
 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__)                   \
@@ -3151,7 +3109,6 @@ extern struct sched_entity *__pick_root_entity(struct cfs_rq *cfs_rq);
 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
 
-#ifdef CONFIG_SCHED_DEBUG
 extern bool sched_debug_verbose;
 
 extern void print_cfs_stats(struct seq_file *m, int cpu);
@@ -3162,15 +3119,12 @@ extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
 
 extern void resched_latency_warn(int cpu, u64 latency);
-# ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_NUMA_BALANCING
 extern void show_numa_stats(struct task_struct *p, struct seq_file *m);
 extern void
 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
                 unsigned long tpf, unsigned long gsf, unsigned long gpf);
-# endif /* CONFIG_NUMA_BALANCING */
-#else /* !CONFIG_SCHED_DEBUG: */
-static inline void resched_latency_warn(int cpu, u64 latency) { }
-#endif /* !CONFIG_SCHED_DEBUG */
+#endif /* CONFIG_NUMA_BALANCING */
 
 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
 extern void init_rt_rq(struct rt_rq *rt_rq);

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 95bde793651c6fc78beb89e7cf1b95fa1781ed4c..f1ebc60d967f5e7c123a2662e2efece92a2a2b90 100644 (file)
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -19,8 +19,6 @@ void sched_domains_mutex_unlock(void)
 static cpumask_var_t sched_domains_tmpmask;
 static cpumask_var_t sched_domains_tmpmask2;
 
-#ifdef CONFIG_SCHED_DEBUG
-
 static int __init sched_debug_setup(char *str)
 {
        sched_debug_verbose = true;
@@ -159,15 +157,6 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
                        break;
        }
 }
-#else /* !CONFIG_SCHED_DEBUG */
-
-# define sched_debug_verbose 0
-# define sched_domain_debug(sd, cpu) do { } while (0)
-static inline bool sched_debug(void)
-{
-       return false;
-}
-#endif /* CONFIG_SCHED_DEBUG */
 
 /* Generate a mask of SD flags with the SDF_NEEDS_GROUPS metaflag */
 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_NEEDS_GROUPS)) |
@@ -2283,9 +2272,7 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
                        if (!sgc)
                                return -ENOMEM;
 
-#ifdef CONFIG_SCHED_DEBUG
                        sgc->id = j;
-#endif
 
                        *per_cpu_ptr(sdd->sgc, j) = sgc;
                }