233 lines
5.5 KiB
C
233 lines
5.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* /proc/schedstat implementation
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*/
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#include "sched.h"
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void __update_stats_wait_start(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats)
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{
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u64 wait_start, prev_wait_start;
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wait_start = rq_clock(rq);
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prev_wait_start = schedstat_val(stats->wait_start);
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if (p && likely(wait_start > prev_wait_start))
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wait_start -= prev_wait_start;
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__schedstat_set(stats->wait_start, wait_start);
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}
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void __update_stats_wait_end(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats)
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{
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u64 delta = rq_clock(rq) - schedstat_val(stats->wait_start);
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if (p) {
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if (task_on_rq_migrating(p)) {
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/*
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* Preserve migrating task's wait time so wait_start
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* time stamp can be adjusted to accumulate wait time
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* prior to migration.
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*/
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__schedstat_set(stats->wait_start, delta);
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return;
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}
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trace_sched_stat_wait(p, delta);
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}
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__schedstat_set(stats->wait_max,
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max(schedstat_val(stats->wait_max), delta));
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__schedstat_inc(stats->wait_count);
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__schedstat_add(stats->wait_sum, delta);
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__schedstat_set(stats->wait_start, 0);
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}
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void __update_stats_enqueue_sleeper(struct rq *rq, struct task_struct *p,
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struct sched_statistics *stats)
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{
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u64 sleep_start, block_start;
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sleep_start = schedstat_val(stats->sleep_start);
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block_start = schedstat_val(stats->block_start);
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if (sleep_start) {
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u64 delta = rq_clock(rq) - sleep_start;
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if ((s64)delta < 0)
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delta = 0;
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if (unlikely(delta > schedstat_val(stats->sleep_max)))
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__schedstat_set(stats->sleep_max, delta);
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__schedstat_set(stats->sleep_start, 0);
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__schedstat_add(stats->sum_sleep_runtime, delta);
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if (p) {
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account_scheduler_latency(p, delta >> 10, 1);
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trace_sched_stat_sleep(p, delta);
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}
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}
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if (block_start) {
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u64 delta = rq_clock(rq) - block_start;
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if ((s64)delta < 0)
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delta = 0;
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if (unlikely(delta > schedstat_val(stats->block_max)))
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__schedstat_set(stats->block_max, delta);
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__schedstat_set(stats->block_start, 0);
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__schedstat_add(stats->sum_sleep_runtime, delta);
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__schedstat_add(stats->sum_block_runtime, delta);
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if (p) {
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if (p->in_iowait) {
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__schedstat_add(stats->iowait_sum, delta);
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__schedstat_inc(stats->iowait_count);
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trace_sched_stat_iowait(p, delta);
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}
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trace_sched_stat_blocked(p, delta);
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/*
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* Blocking time is in units of nanosecs, so shift by
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* 20 to get a milliseconds-range estimation of the
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* amount of time that the task spent sleeping:
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*/
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if (unlikely(prof_on == SLEEP_PROFILING)) {
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profile_hits(SLEEP_PROFILING,
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(void *)get_wchan(p),
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delta >> 20);
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}
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account_scheduler_latency(p, delta >> 10, 0);
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}
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}
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}
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/*
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* Current schedstat API version.
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*
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* Bump this up when changing the output format or the meaning of an existing
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* format, so that tools can adapt (or abort)
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*/
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#define SCHEDSTAT_VERSION 15
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static int show_schedstat(struct seq_file *seq, void *v)
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{
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int cpu;
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if (v == (void *)1) {
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seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
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seq_printf(seq, "timestamp %lu\n", jiffies);
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} else {
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struct rq *rq;
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#ifdef CONFIG_SMP
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struct sched_domain *sd;
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int dcount = 0;
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#endif
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cpu = (unsigned long)(v - 2);
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rq = cpu_rq(cpu);
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/* runqueue-specific stats */
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seq_printf(seq,
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"cpu%d %u 0 %u %u %u %u %llu %llu %lu",
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cpu, rq->yld_count,
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rq->sched_count, rq->sched_goidle,
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rq->ttwu_count, rq->ttwu_local,
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rq->rq_cpu_time,
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rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
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seq_printf(seq, "\n");
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#ifdef CONFIG_SMP
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/* domain-specific stats */
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rcu_read_lock();
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for_each_domain(cpu, sd) {
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enum cpu_idle_type itype;
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seq_printf(seq, "domain%d %*pb", dcount++,
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cpumask_pr_args(sched_domain_span(sd)));
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for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
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itype++) {
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seq_printf(seq, " %u %u %u %u %u %u %u %u",
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sd->lb_count[itype],
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sd->lb_balanced[itype],
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sd->lb_failed[itype],
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sd->lb_imbalance[itype],
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sd->lb_gained[itype],
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sd->lb_hot_gained[itype],
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sd->lb_nobusyq[itype],
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sd->lb_nobusyg[itype]);
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}
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seq_printf(seq,
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" %u %u %u %u %u %u %u %u %u %u %u %u\n",
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sd->alb_count, sd->alb_failed, sd->alb_pushed,
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sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed,
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sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed,
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sd->ttwu_wake_remote, sd->ttwu_move_affine,
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sd->ttwu_move_balance);
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}
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rcu_read_unlock();
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#endif
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}
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return 0;
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}
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/*
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* This iterator needs some explanation.
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* It returns 1 for the header position.
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* This means 2 is cpu 0.
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* In a hotplugged system some CPUs, including cpu 0, may be missing so we have
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* to use cpumask_* to iterate over the CPUs.
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*/
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static void *schedstat_start(struct seq_file *file, loff_t *offset)
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{
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unsigned long n = *offset;
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if (n == 0)
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return (void *) 1;
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n--;
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if (n > 0)
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n = cpumask_next(n - 1, cpu_online_mask);
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else
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n = cpumask_first(cpu_online_mask);
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*offset = n + 1;
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if (n < nr_cpu_ids)
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return (void *)(unsigned long)(n + 2);
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return NULL;
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}
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static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
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{
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(*offset)++;
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return schedstat_start(file, offset);
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}
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static void schedstat_stop(struct seq_file *file, void *data)
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{
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}
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static const struct seq_operations schedstat_sops = {
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.start = schedstat_start,
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.next = schedstat_next,
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.stop = schedstat_stop,
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.show = show_schedstat,
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};
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static int __init proc_schedstat_init(void)
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{
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proc_create_seq("schedstat", 0, NULL, &schedstat_sops);
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return 0;
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}
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subsys_initcall(proc_schedstat_init);
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