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linux/kernel/sched/debug.c
Peter Zijlstra 13e099d2f7 sched/debug: Fix printing large integers on 32-bit platforms 
Some numbers like nr_running and nr_uninterruptible are fundamentally
unsigned since its impossible to have a negative amount of tasks, yet
we still print them as signed to easily recognise the underflow
condition.

rq->nr_uninterruptible has 'special' accounting and can in fact very
easily become negative on a per-cpu basis.

It was noted that since the P() macro assumes things are long long and
the promotion of unsigned 'int/long' to long long on 32bit doesn't
sign extend we print silly large numbers instead of the easier to read
signed numbers.

Therefore extend the P() macro to not require the sign extention.

Reported-by: Diwakar Tundlam <dtundlam@nvidia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-gk5tm8t2n4ix2vkpns42uqqp@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-14 15:05:28 +02:00

516 lines
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/*
* kernel/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>
#include "sched.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: %d\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) \
do { \
if (sizeof(rq->x) == 4) \
SEQ_printf(m, " .%-30s: %ld\n", #x, (long)(rq->x)); \
else \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x));\
} while (0)
#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_count);
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
#endif
P(ttwu_count);
P(ttwu_local);
#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;
}
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(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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