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linux/kernel/sched_debug.c
Arjan van de Ven 6d082592b6 sched: keep total / count stats in addition to the max for 
Right now, the linux kernel (with scheduler statistics enabled) keeps track
of the maximum time a process is waiting to be scheduled. While the maximum
is a very useful metric, tracking average and total is equally useful
(at least for latencytop) to figure out the accumulated effect of scheduler
delays. The accumulated effect is important to judge the performance impact
of scheduler tuning/behavior.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:35 +01:00

402 lines
9.3 KiB
C
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/*
* kernel/time/sched_debug.c
*
* Print the CFS rbtree
*
* Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/utsname.h>
/*
* This allows printing both to /proc/sched_debug and
* to the console
*/
#define SEQ_printf(m, x...) \
do { \
if (m) \
seq_printf(m, x); \
else \
printk(x); \
} while (0)
/*
* Ease the printing of nsec fields:
*/
static long long nsec_high(unsigned long long nsec)
{
if ((long long)nsec < 0) {
nsec = -nsec;
do_div(nsec, 1000000);
return -nsec;
}
do_div(nsec, 1000000);
return nsec;
}
static unsigned long nsec_low(unsigned long long nsec)
{
if ((long long)nsec < 0)
nsec = -nsec;
return do_div(nsec, 1000000);
}
#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
static void
print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
{
if (rq->curr == p)
SEQ_printf(m, "R");
else
SEQ_printf(m, " ");
SEQ_printf(m, "%15s %5d %9Ld.%06ld %9Ld %5d ",
p->comm, p->pid,
SPLIT_NS(p->se.vruntime),
(long long)(p->nvcsw + p->nivcsw),
p->prio);
#ifdef CONFIG_SCHEDSTATS
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld\n",
SPLIT_NS(p->se.vruntime),
SPLIT_NS(p->se.sum_exec_runtime),
SPLIT_NS(p->se.sum_sleep_runtime));
#else
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld\n",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
#endif
}
static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
{
struct task_struct *g, *p;
unsigned long flags;
SEQ_printf(m,
"\nrunnable tasks:\n"
" task PID tree-key switches prio"
" exec-runtime sum-exec sum-sleep\n"
"------------------------------------------------------"
"----------------------------------------------------\n");
read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, p) {
if (!p->se.on_rq || task_cpu(p) != rq_cpu)
continue;
print_task(m, rq, p);
} while_each_thread(g, p);
read_unlock_irqrestore(&tasklist_lock, flags);
}
void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
{
s64 MIN_vruntime = -1, min_vruntime, max_vruntime = -1,
spread, rq0_min_vruntime, spread0;
struct rq *rq = &per_cpu(runqueues, cpu);
struct sched_entity *last;
unsigned long flags;
SEQ_printf(m, "\ncfs_rq\n");
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
SPLIT_NS(cfs_rq->exec_clock));
spin_lock_irqsave(&rq->lock, flags);
if (cfs_rq->rb_leftmost)
MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime;
last = __pick_last_entity(cfs_rq);
if (last)
max_vruntime = last->vruntime;
min_vruntime = rq->cfs.min_vruntime;
rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime;
spin_unlock_irqrestore(&rq->lock, flags);
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime",
SPLIT_NS(MIN_vruntime));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime",
SPLIT_NS(min_vruntime));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "max_vruntime",
SPLIT_NS(max_vruntime));
spread = max_vruntime - MIN_vruntime;
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread",
SPLIT_NS(spread));
spread0 = min_vruntime - rq0_min_vruntime;
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread0",
SPLIT_NS(spread0));
SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_SCHEDSTATS
SEQ_printf(m, " .%-30s: %d\n", "bkl_count",
rq->bkl_count);
#endif
SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over",
cfs_rq->nr_spread_over);
}
static void print_cpu(struct seq_file *m, int cpu)
{
struct rq *rq = &per_cpu(runqueues, cpu);
#ifdef CONFIG_X86
{
unsigned int freq = cpu_khz ? : 1;
SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
cpu, freq / 1000, (freq % 1000));
}
#else
SEQ_printf(m, "\ncpu#%d\n", cpu);
#endif
#define P(x) \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x))
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
P(nr_running);
SEQ_printf(m, " .%-30s: %lu\n", "load",
rq->load.weight);
P(nr_switches);
P(nr_load_updates);
P(nr_uninterruptible);
SEQ_printf(m, " .%-30s: %lu\n", "jiffies", jiffies);
PN(next_balance);
P(curr->pid);
PN(clock);
PN(idle_clock);
PN(prev_clock_raw);
P(clock_warps);
P(clock_overflows);
P(clock_underflows);
P(clock_deep_idle_events);
PN(clock_max_delta);
P(cpu_load[0]);
P(cpu_load[1]);
P(cpu_load[2]);
P(cpu_load[3]);
P(cpu_load[4]);
#undef P
#undef PN
print_cfs_stats(m, cpu);
print_rq(m, rq, cpu);
}
static int sched_debug_show(struct seq_file *m, void *v)
{
u64 now = ktime_to_ns(ktime_get());
int cpu;
SEQ_printf(m, "Sched Debug Version: v0.07, %s %.*s\n",
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
SEQ_printf(m, "now at %Lu.%06ld msecs\n", SPLIT_NS(now));
#define P(x) \
SEQ_printf(m, " .%-40s: %Ld\n", #x, (long long)(x))
#define PN(x) \
SEQ_printf(m, " .%-40s: %Ld.%06ld\n", #x, SPLIT_NS(x))
PN(sysctl_sched_latency);
PN(sysctl_sched_min_granularity);
PN(sysctl_sched_wakeup_granularity);
PN(sysctl_sched_batch_wakeup_granularity);
PN(sysctl_sched_child_runs_first);
P(sysctl_sched_features);
#undef PN
#undef P
for_each_online_cpu(cpu)
print_cpu(m, cpu);
SEQ_printf(m, "\n");
return 0;
}
static void sysrq_sched_debug_show(void)
{
sched_debug_show(NULL, NULL);
}
static int sched_debug_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_debug_show, NULL);
}
static const struct file_operations sched_debug_fops = {
.open = sched_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init init_sched_debug_procfs(void)
{
struct proc_dir_entry *pe;
pe = create_proc_entry("sched_debug", 0644, NULL);
if (!pe)
return -ENOMEM;
pe->proc_fops = &sched_debug_fops;
return 0;
}
__initcall(init_sched_debug_procfs);
void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
unsigned long nr_switches;
unsigned long flags;
int num_threads = 1;
rcu_read_lock();
if (lock_task_sighand(p, &flags)) {
num_threads = atomic_read(&p->signal->count);
unlock_task_sighand(p, &flags);
}
rcu_read_unlock();
SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid, num_threads);
SEQ_printf(m,
"---------------------------------------------------------\n");
#define __P(F) \
SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)F)
#define P(F) \
SEQ_printf(m, "%-35s:%21Ld\n", #F, (long long)p->F)
#define __PN(F) \
SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN(F) \
SEQ_printf(m, "%-35s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
PN(se.wait_start);
PN(se.sleep_start);
PN(se.block_start);
PN(se.sleep_max);
PN(se.block_max);
PN(se.exec_max);
PN(se.slice_max);
PN(se.wait_max);
PN(se.wait_sum);
P(se.wait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
P(se.nr_migrations_cold);
P(se.nr_failed_migrations_affine);
P(se.nr_failed_migrations_running);
P(se.nr_failed_migrations_hot);
P(se.nr_forced_migrations);
P(se.nr_forced2_migrations);
P(se.nr_wakeups);
P(se.nr_wakeups_sync);
P(se.nr_wakeups_migrate);
P(se.nr_wakeups_local);
P(se.nr_wakeups_remote);
P(se.nr_wakeups_affine);
P(se.nr_wakeups_affine_attempts);
P(se.nr_wakeups_passive);
P(se.nr_wakeups_idle);
{
u64 avg_atom, avg_per_cpu;
avg_atom = p->se.sum_exec_runtime;
if (nr_switches)
do_div(avg_atom, nr_switches);
else
avg_atom = -1LL;
avg_per_cpu = p->se.sum_exec_runtime;
if (p->se.nr_migrations) {
avg_per_cpu = div64_64(avg_per_cpu,
p->se.nr_migrations);
} else {
avg_per_cpu = -1LL;
}
__PN(avg_atom);
__PN(avg_per_cpu);
}
#endif
__P(nr_switches);
SEQ_printf(m, "%-35s:%21Ld\n",
"nr_voluntary_switches", (long long)p->nvcsw);
SEQ_printf(m, "%-35s:%21Ld\n",
"nr_involuntary_switches", (long long)p->nivcsw);
P(se.load.weight);
P(policy);
P(prio);
#undef PN
#undef __PN
#undef P
#undef __P
{
u64 t0, t1;
t0 = sched_clock();
t1 = sched_clock();
SEQ_printf(m, "%-35s:%21Ld\n",
"clock-delta", (long long)(t1-t0));
}
}
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
p->se.wait_max = 0;
p->se.wait_sum = 0;
p->se.wait_count = 0;
p->se.sleep_max = 0;
p->se.sum_sleep_runtime = 0;
p->se.block_max = 0;
p->se.exec_max = 0;
p->se.slice_max = 0;
p->se.nr_migrations = 0;
p->se.nr_migrations_cold = 0;
p->se.nr_failed_migrations_affine = 0;
p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0;
p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0;
p->se.nr_wakeups_migrate = 0;
p->se.nr_wakeups_local = 0;
p->se.nr_wakeups_remote = 0;
p->se.nr_wakeups_affine = 0;
p->se.nr_wakeups_affine_attempts = 0;
p->se.nr_wakeups_passive = 0;
p->se.nr_wakeups_idle = 0;
p->sched_info.bkl_count = 0;
#endif
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
p->nvcsw = 0;
p->nivcsw = 0;
}
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