diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 26 | ||||
| -rw-r--r-- | kernel/sysctl.c | 16 |
2 files changed, 42 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 98740228ed32..1da6091b54f3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -30,6 +30,7 @@ #include <linux/mempolicy.h> #include <linux/migrate.h> #include <linux/task_work.h> +#include <linux/ratelimit.h> #include <trace/events/sched.h> @@ -122,6 +123,11 @@ unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL; unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL; #endif +#ifdef CONFIG_SCHEDSTATS +unsigned int sysctl_sched_latency_panic_threshold; +unsigned int sysctl_sched_latency_warn_threshold; +#endif /* CONFIG_SCHEDSTATS */ + static inline void update_load_add(struct load_weight *lw, unsigned long inc) { lw->weight += inc; @@ -750,6 +756,25 @@ static void update_curr_fair(struct rq *rq) } #ifdef CONFIG_SCHEDSTATS +static inline void check_for_high_latency(struct task_struct *p, u64 latency_us) +{ + int do_warn, do_panic; + const char *fmt = "excessive latency comm=%s pid=%d latency=%llu(us)\n"; + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + do_warn = (sysctl_sched_latency_warn_threshold && + latency_us > sysctl_sched_latency_warn_threshold); + do_panic = (sysctl_sched_latency_panic_threshold && + latency_us > sysctl_sched_latency_panic_threshold); + if (unlikely(do_panic || (do_warn && __ratelimit(&rs)))) { + if (do_panic) + panic(fmt, p->comm, p->pid, latency_us); + else + printk_deferred(fmt, p->comm, p->pid, latency_us); + } +} + static inline void update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se) { @@ -780,6 +805,7 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) return; } trace_sched_stat_wait(p, delta); + check_for_high_latency(p, delta >> 10); } se->statistics.wait_max = max(se->statistics.wait_max, delta); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 16e465103020..188c7fabeec0 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -593,6 +593,22 @@ static struct ctl_table kern_table[] = { .extra1 = &one, }, #endif +#ifdef CONFIG_SCHEDSTATS + { + .procname = "sched_latency_panic_threshold_us", + .data = &sysctl_sched_latency_panic_threshold, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + }, + { + .procname = "sched_latency_warn_threshold_us", + .data = &sysctl_sched_latency_warn_threshold, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + }, +#endif #ifdef CONFIG_PROVE_LOCKING { .procname = "prove_locking", |