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linux/kernel/sched_debug.c
Peter Zijlstra fd2f4419b4 sched: Provide p->on_rq 
Provide a generic p->on_rq because the p->se.on_rq semantics are
unfavourable for lockless wakeups but needed for sched_fair.

In particular, p->on_rq is only cleared when we actually dequeue the
task in schedule() and not on any random dequeue as done by things
like __migrate_task() and __sched_setscheduler().

This also allows us to remove p->se usage from !sched_fair code.

Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl
2011-04-14 08:52:35 +02:00

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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>
static DEFINE_SPINLOCK(sched_debug_lock);
/*
* 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)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
{
struct sched_entity *se = tg->se[cpu];
if (!se)
return;
#define P(F) \
SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
#define PN(F) \
SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
PN(se->exec_start);
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
PN(se->statistics.wait_start);
PN(se->statistics.sleep_start);
PN(se->statistics.block_start);
PN(se->statistics.sleep_max);
PN(se->statistics.block_max);
PN(se->statistics.exec_max);
PN(se->statistics.slice_max);
PN(se->statistics.wait_max);
PN(se->statistics.wait_sum);
P(se->statistics.wait_count);
#endif
P(se->load.weight);
#undef PN
#undef P
}
#endif
#ifdef CONFIG_CGROUP_SCHED
static char group_path[PATH_MAX];
static char *task_group_path(struct task_group *tg)
{
if (autogroup_path(tg, group_path, PATH_MAX))
return group_path;
/*
* May be NULL if the underlying cgroup isn't fully-created yet
*/
if (!tg->css.cgroup) {
group_path[0] = '\0';
return group_path;
}
cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
return group_path;
}
#endif
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",
SPLIT_NS(p->se.vruntime),
SPLIT_NS(p->se.sum_exec_runtime),
SPLIT_NS(p->se.statistics.sum_sleep_runtime));
#else
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
#endif
#ifdef CONFIG_CGROUP_SCHED
SEQ_printf(m, " %s", task_group_path(task_group(p)));
#endif
SEQ_printf(m, "\n");
}
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->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 = cpu_rq(cpu);
struct sched_entity *last;
unsigned long flags;
#ifdef CONFIG_FAIR_GROUP_SCHED
SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
#else
SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
#endif
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
SPLIT_NS(cfs_rq->exec_clock));
raw_spin_lock_irqsave(&rq->lock, flags);
if (cfs_rq->rb_leftmost)
MIN_vruntime = (__pick_first_entity(cfs_rq))->vruntime;
last = __pick_last_entity(cfs_rq);
if (last)
max_vruntime = last->vruntime;
min_vruntime = cfs_rq->min_vruntime;
rq0_min_vruntime = cpu_rq(0)->cfs.min_vruntime;
raw_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: %d\n", "nr_spread_over",
cfs_rq->nr_spread_over);
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_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "load_avg",
SPLIT_NS(cfs_rq->load_avg));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "load_period",
SPLIT_NS(cfs_rq->load_period));
SEQ_printf(m, " .%-30s: %ld\n", "load_contrib",
cfs_rq->load_contribution);
SEQ_printf(m, " .%-30s: %d\n", "load_tg",
atomic_read(&cfs_rq->tg->load_weight));
#endif
print_cfs_group_stats(m, cpu, cfs_rq->tg);
#endif
}
void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
{
#ifdef CONFIG_RT_GROUP_SCHED
SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
#else
SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
#endif
#define P(x) \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
P(rt_nr_running);
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
#undef PN
#undef P
}
extern __read_mostly int sched_clock_running;
static void print_cpu(struct seq_file *m, int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
#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);
PN(next_balance);
P(curr->pid);
PN(clock);
P(cpu_load[0]);
P(cpu_load[1]);
P(cpu_load[2]);
P(cpu_load[3]);
P(cpu_load[4]);
#undef P
#undef PN
#ifdef CONFIG_SCHEDSTATS
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
P(yld_count);
P(sched_switch);
P(sched_count);
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
#endif
P(ttwu_count);
P(ttwu_local);
SEQ_printf(m, " .%-30s: %d\n", "bkl_count",
rq->rq_sched_info.bkl_count);
#undef P
#undef P64
#endif
spin_lock_irqsave(&sched_debug_lock, flags);
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);
rcu_read_lock();
print_rq(m, rq, cpu);
rcu_read_unlock();
spin_unlock_irqrestore(&sched_debug_lock, flags);
}
static const char *sched_tunable_scaling_names[] = {
"none",
"logaritmic",
"linear"
};
static int sched_debug_show(struct seq_file *m, void *v)
{
u64 ktime, sched_clk, cpu_clk;
unsigned long flags;
int cpu;
local_irq_save(flags);
ktime = ktime_to_ns(ktime_get());
sched_clk = sched_clock();
cpu_clk = local_clock();
local_irq_restore(flags);
SEQ_printf(m, "Sched Debug Version: v0.10, %s %.*s\n",
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
#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(ktime);
PN(sched_clk);
PN(cpu_clk);
P(jiffies);
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
P(sched_clock_stable);
#endif
#undef PN
#undef P
SEQ_printf(m, "\n");
SEQ_printf(m, "sysctl_sched\n");
#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);
P(sysctl_sched_child_runs_first);
P(sysctl_sched_features);
#undef PN
#undef P
SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
sysctl_sched_tunable_scaling,
sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
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 = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
if (!pe)
return -ENOMEM;
return 0;
}
__initcall(init_sched_debug_procfs);
void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
{
unsigned long nr_switches;
SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, p->pid,
get_nr_threads(p));
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.statistics.wait_start);
PN(se.statistics.sleep_start);
PN(se.statistics.block_start);
PN(se.statistics.sleep_max);
PN(se.statistics.block_max);
PN(se.statistics.exec_max);
PN(se.statistics.slice_max);
PN(se.statistics.wait_max);
PN(se.statistics.wait_sum);
P(se.statistics.wait_count);
PN(se.statistics.iowait_sum);
P(se.statistics.iowait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
P(se.statistics.nr_migrations_cold);
P(se.statistics.nr_failed_migrations_affine);
P(se.statistics.nr_failed_migrations_running);
P(se.statistics.nr_failed_migrations_hot);
P(se.statistics.nr_forced_migrations);
P(se.statistics.nr_wakeups);
P(se.statistics.nr_wakeups_sync);
P(se.statistics.nr_wakeups_migrate);
P(se.statistics.nr_wakeups_local);
P(se.statistics.nr_wakeups_remote);
P(se.statistics.nr_wakeups_affine);
P(se.statistics.nr_wakeups_affine_attempts);
P(se.statistics.nr_wakeups_passive);
P(se.statistics.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_u64(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
{
unsigned int this_cpu = raw_smp_processor_id();
u64 t0, t1;
t0 = cpu_clock(this_cpu);
t1 = cpu_clock(this_cpu);
SEQ_printf(m, "%-35s:%21Ld\n",
"clock-delta", (long long)(t1-t0));
}
}
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
}
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