linux/kernel/sched/debug.c
Linus Torvalds c7b92e8969 Fix a cfs_rq->h_nr_runnable accounting bug that trips up a
defensive SCHED_WARN_ON() on certain workloads. The bug is
 believed to be (accidentally) self-correcting, hence no
 behavioral side effects are expected.
 
 Also print se.slice in debug output, since this value can now be
 set via the syscall ABI and can be useful to track.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Fix a cfs_rq->h_nr_runnable accounting bug that trips up a defensive
  SCHED_WARN_ON() on certain workloads. The bug is believed to be
  (accidentally) self-correcting, hence no behavioral side effects are
  expected.

  Also print se.slice in debug output, since this value can now be set
  via the syscall ABI and can be useful to track"

* tag 'sched-urgent-2025-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Provide slice length for fair tasks
  sched/fair: Fix inaccurate h_nr_runnable accounting with delayed dequeue
2025-02-08 11:16:22 -08:00

1304 lines
31 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* kernel/sched/debug.c
*
* Print the CFS rbtree and other debugging details
*
* Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
*/
/*
* This allows printing both to /sys/kernel/debug/sched/debug and
* to the console
*/
#define SEQ_printf(m, x...) \
do { \
if (m) \
seq_printf(m, x); \
else \
pr_cont(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)
#define SCHED_FEAT(name, enabled) \
#name ,
static const char * const sched_feat_names[] = {
#include "features.h"
};
#undef SCHED_FEAT
static int sched_feat_show(struct seq_file *m, void *v)
{
int i;
for (i = 0; i < __SCHED_FEAT_NR; i++) {
if (!(sysctl_sched_features & (1UL << i)))
seq_puts(m, "NO_");
seq_printf(m, "%s ", sched_feat_names[i]);
}
seq_puts(m, "\n");
return 0;
}
#ifdef CONFIG_JUMP_LABEL
#define jump_label_key__true STATIC_KEY_INIT_TRUE
#define jump_label_key__false STATIC_KEY_INIT_FALSE
#define SCHED_FEAT(name, enabled) \
jump_label_key__##enabled ,
struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
#include "features.h"
};
#undef SCHED_FEAT
static void sched_feat_disable(int i)
{
static_key_disable_cpuslocked(&sched_feat_keys[i]);
}
static void sched_feat_enable(int i)
{
static_key_enable_cpuslocked(&sched_feat_keys[i]);
}
#else
static void sched_feat_disable(int i) { };
static void sched_feat_enable(int i) { };
#endif /* CONFIG_JUMP_LABEL */
static int sched_feat_set(char *cmp)
{
int i;
int neg = 0;
if (strncmp(cmp, "NO_", 3) == 0) {
neg = 1;
cmp += 3;
}
i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp);
if (i < 0)
return i;
if (neg) {
sysctl_sched_features &= ~(1UL << i);
sched_feat_disable(i);
} else {
sysctl_sched_features |= (1UL << i);
sched_feat_enable(i);
}
return 0;
}
static ssize_t
sched_feat_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[64];
char *cmp;
int ret;
struct inode *inode;
if (cnt > 63)
cnt = 63;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
cmp = strstrip(buf);
/* Ensure the static_key remains in a consistent state */
inode = file_inode(filp);
cpus_read_lock();
inode_lock(inode);
ret = sched_feat_set(cmp);
inode_unlock(inode);
cpus_read_unlock();
if (ret < 0)
return ret;
*ppos += cnt;
return cnt;
}
static int sched_feat_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_feat_show, NULL);
}
static const struct file_operations sched_feat_fops = {
.open = sched_feat_open,
.write = sched_feat_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#ifdef CONFIG_SMP
static ssize_t sched_scaling_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[16];
unsigned int scaling;
if (cnt > 15)
cnt = 15;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = '\0';
if (kstrtouint(buf, 10, &scaling))
return -EINVAL;
if (scaling >= SCHED_TUNABLESCALING_END)
return -EINVAL;
sysctl_sched_tunable_scaling = scaling;
if (sched_update_scaling())
return -EINVAL;
*ppos += cnt;
return cnt;
}
static int sched_scaling_show(struct seq_file *m, void *v)
{
seq_printf(m, "%d\n", sysctl_sched_tunable_scaling);
return 0;
}
static int sched_scaling_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_scaling_show, NULL);
}
static const struct file_operations sched_scaling_fops = {
.open = sched_scaling_open,
.write = sched_scaling_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* SMP */
#ifdef CONFIG_PREEMPT_DYNAMIC
static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
char buf[16];
int mode;
if (cnt > 15)
cnt = 15;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
mode = sched_dynamic_mode(strstrip(buf));
if (mode < 0)
return mode;
sched_dynamic_update(mode);
*ppos += cnt;
return cnt;
}
static int sched_dynamic_show(struct seq_file *m, void *v)
{
static const char * preempt_modes[] = {
"none", "voluntary", "full", "lazy",
};
int j = ARRAY_SIZE(preempt_modes) - !IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY);
int i = IS_ENABLED(CONFIG_PREEMPT_RT) * 2;
for (; i < j; i++) {
if (preempt_dynamic_mode == i)
seq_puts(m, "(");
seq_puts(m, preempt_modes[i]);
if (preempt_dynamic_mode == i)
seq_puts(m, ")");
seq_puts(m, " ");
}
seq_puts(m, "\n");
return 0;
}
static int sched_dynamic_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_dynamic_show, NULL);
}
static const struct file_operations sched_dynamic_fops = {
.open = sched_dynamic_open,
.write = sched_dynamic_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_PREEMPT_DYNAMIC */
__read_mostly bool sched_debug_verbose;
#ifdef CONFIG_SMP
static struct dentry *sd_dentry;
static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
ssize_t result;
bool orig;
cpus_read_lock();
mutex_lock(&sched_domains_mutex);
orig = sched_debug_verbose;
result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
if (sched_debug_verbose && !orig)
update_sched_domain_debugfs();
else if (!sched_debug_verbose && orig) {
debugfs_remove(sd_dentry);
sd_dentry = NULL;
}
mutex_unlock(&sched_domains_mutex);
cpus_read_unlock();
return result;
}
#else
#define sched_verbose_write debugfs_write_file_bool
#endif
static const struct file_operations sched_verbose_fops = {
.read = debugfs_read_file_bool,
.write = sched_verbose_write,
.open = simple_open,
.llseek = default_llseek,
};
static const struct seq_operations sched_debug_sops;
static int sched_debug_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &sched_debug_sops);
}
static const struct file_operations sched_debug_fops = {
.open = sched_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
enum dl_param {
DL_RUNTIME = 0,
DL_PERIOD,
};
static unsigned long fair_server_period_max = (1UL << 22) * NSEC_PER_USEC; /* ~4 seconds */
static unsigned long fair_server_period_min = (100) * NSEC_PER_USEC; /* 100 us */
static ssize_t sched_fair_server_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos, enum dl_param param)
{
long cpu = (long) ((struct seq_file *) filp->private_data)->private;
struct rq *rq = cpu_rq(cpu);
u64 runtime, period;
size_t err;
int retval;
u64 value;
err = kstrtoull_from_user(ubuf, cnt, 10, &value);
if (err)
return err;
scoped_guard (rq_lock_irqsave, rq) {
runtime = rq->fair_server.dl_runtime;
period = rq->fair_server.dl_period;
switch (param) {
case DL_RUNTIME:
if (runtime == value)
break;
runtime = value;
break;
case DL_PERIOD:
if (value == period)
break;
period = value;
break;
}
if (runtime > period ||
period > fair_server_period_max ||
period < fair_server_period_min) {
return -EINVAL;
}
if (rq->cfs.h_nr_queued) {
update_rq_clock(rq);
dl_server_stop(&rq->fair_server);
}
retval = dl_server_apply_params(&rq->fair_server, runtime, period, 0);
if (retval)
cnt = retval;
if (!runtime)
printk_deferred("Fair server disabled in CPU %d, system may crash due to starvation.\n",
cpu_of(rq));
if (rq->cfs.h_nr_queued)
dl_server_start(&rq->fair_server);
}
*ppos += cnt;
return cnt;
}
static size_t sched_fair_server_show(struct seq_file *m, void *v, enum dl_param param)
{
unsigned long cpu = (unsigned long) m->private;
struct rq *rq = cpu_rq(cpu);
u64 value;
switch (param) {
case DL_RUNTIME:
value = rq->fair_server.dl_runtime;
break;
case DL_PERIOD:
value = rq->fair_server.dl_period;
break;
}
seq_printf(m, "%llu\n", value);
return 0;
}
static ssize_t
sched_fair_server_runtime_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_RUNTIME);
}
static int sched_fair_server_runtime_show(struct seq_file *m, void *v)
{
return sched_fair_server_show(m, v, DL_RUNTIME);
}
static int sched_fair_server_runtime_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_fair_server_runtime_show, inode->i_private);
}
static const struct file_operations fair_server_runtime_fops = {
.open = sched_fair_server_runtime_open,
.write = sched_fair_server_runtime_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static ssize_t
sched_fair_server_period_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
return sched_fair_server_write(filp, ubuf, cnt, ppos, DL_PERIOD);
}
static int sched_fair_server_period_show(struct seq_file *m, void *v)
{
return sched_fair_server_show(m, v, DL_PERIOD);
}
static int sched_fair_server_period_open(struct inode *inode, struct file *filp)
{
return single_open(filp, sched_fair_server_period_show, inode->i_private);
}
static const struct file_operations fair_server_period_fops = {
.open = sched_fair_server_period_open,
.write = sched_fair_server_period_write,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static struct dentry *debugfs_sched;
static void debugfs_fair_server_init(void)
{
struct dentry *d_fair;
unsigned long cpu;
d_fair = debugfs_create_dir("fair_server", debugfs_sched);
if (!d_fair)
return;
for_each_possible_cpu(cpu) {
struct dentry *d_cpu;
char buf[32];
snprintf(buf, sizeof(buf), "cpu%lu", cpu);
d_cpu = debugfs_create_dir(buf, d_fair);
debugfs_create_file("runtime", 0644, d_cpu, (void *) cpu, &fair_server_runtime_fops);
debugfs_create_file("period", 0644, d_cpu, (void *) cpu, &fair_server_period_fops);
}
}
static __init int sched_init_debug(void)
{
struct dentry __maybe_unused *numa;
debugfs_sched = debugfs_create_dir("sched", NULL);
debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops);
debugfs_create_file_unsafe("verbose", 0644, debugfs_sched, &sched_debug_verbose, &sched_verbose_fops);
#ifdef CONFIG_PREEMPT_DYNAMIC
debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops);
#endif
debugfs_create_u32("base_slice_ns", 0644, debugfs_sched, &sysctl_sched_base_slice);
debugfs_create_u32("latency_warn_ms", 0644, debugfs_sched, &sysctl_resched_latency_warn_ms);
debugfs_create_u32("latency_warn_once", 0644, debugfs_sched, &sysctl_resched_latency_warn_once);
#ifdef CONFIG_SMP
debugfs_create_file("tunable_scaling", 0644, debugfs_sched, NULL, &sched_scaling_fops);
debugfs_create_u32("migration_cost_ns", 0644, debugfs_sched, &sysctl_sched_migration_cost);
debugfs_create_u32("nr_migrate", 0644, debugfs_sched, &sysctl_sched_nr_migrate);
mutex_lock(&sched_domains_mutex);
update_sched_domain_debugfs();
mutex_unlock(&sched_domains_mutex);
#endif
#ifdef CONFIG_NUMA_BALANCING
numa = debugfs_create_dir("numa_balancing", debugfs_sched);
debugfs_create_u32("scan_delay_ms", 0644, numa, &sysctl_numa_balancing_scan_delay);
debugfs_create_u32("scan_period_min_ms", 0644, numa, &sysctl_numa_balancing_scan_period_min);
debugfs_create_u32("scan_period_max_ms", 0644, numa, &sysctl_numa_balancing_scan_period_max);
debugfs_create_u32("scan_size_mb", 0644, numa, &sysctl_numa_balancing_scan_size);
debugfs_create_u32("hot_threshold_ms", 0644, numa, &sysctl_numa_balancing_hot_threshold);
#endif
debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops);
debugfs_fair_server_init();
return 0;
}
late_initcall(sched_init_debug);
#ifdef CONFIG_SMP
static cpumask_var_t sd_sysctl_cpus;
static int sd_flags_show(struct seq_file *m, void *v)
{
unsigned long flags = *(unsigned int *)m->private;
int idx;
for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
seq_puts(m, sd_flag_debug[idx].name);
seq_puts(m, " ");
}
seq_puts(m, "\n");
return 0;
}
static int sd_flags_open(struct inode *inode, struct file *file)
{
return single_open(file, sd_flags_show, inode->i_private);
}
static const struct file_operations sd_flags_fops = {
.open = sd_flags_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void register_sd(struct sched_domain *sd, struct dentry *parent)
{
#define SDM(type, mode, member) \
debugfs_create_##type(#member, mode, parent, &sd->member)
SDM(ulong, 0644, min_interval);
SDM(ulong, 0644, max_interval);
SDM(u64, 0644, max_newidle_lb_cost);
SDM(u32, 0644, busy_factor);
SDM(u32, 0644, imbalance_pct);
SDM(u32, 0644, cache_nice_tries);
SDM(str, 0444, name);
#undef SDM
debugfs_create_file("flags", 0444, parent, &sd->flags, &sd_flags_fops);
debugfs_create_file("groups_flags", 0444, parent, &sd->groups->flags, &sd_flags_fops);
debugfs_create_u32("level", 0444, parent, (u32 *)&sd->level);
}
void update_sched_domain_debugfs(void)
{
int cpu, i;
/*
* This can unfortunately be invoked before sched_debug_init() creates
* the debug directory. Don't touch sd_sysctl_cpus until then.
*/
if (!debugfs_sched)
return;
if (!sched_debug_verbose)
return;
if (!cpumask_available(sd_sysctl_cpus)) {
if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL))
return;
cpumask_copy(sd_sysctl_cpus, cpu_possible_mask);
}
if (!sd_dentry) {
sd_dentry = debugfs_create_dir("domains", debugfs_sched);
/* rebuild sd_sysctl_cpus if empty since it gets cleared below */
if (cpumask_empty(sd_sysctl_cpus))
cpumask_copy(sd_sysctl_cpus, cpu_online_mask);
}
for_each_cpu(cpu, sd_sysctl_cpus) {
struct sched_domain *sd;
struct dentry *d_cpu;
char buf[32];
snprintf(buf, sizeof(buf), "cpu%d", cpu);
debugfs_lookup_and_remove(buf, sd_dentry);
d_cpu = debugfs_create_dir(buf, sd_dentry);
i = 0;
for_each_domain(cpu, sd) {
struct dentry *d_sd;
snprintf(buf, sizeof(buf), "domain%d", i);
d_sd = debugfs_create_dir(buf, d_cpu);
register_sd(sd, d_sd);
i++;
}
__cpumask_clear_cpu(cpu, sd_sysctl_cpus);
}
}
void dirty_sched_domain_sysctl(int cpu)
{
if (cpumask_available(sd_sysctl_cpus))
__cpumask_set_cpu(cpu, sd_sysctl_cpus);
}
#endif /* CONFIG_SMP */
#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];
#define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
#define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
#F, (long long)schedstat_val(stats->F))
#define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
#define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
#F, SPLIT_NS((long long)schedstat_val(stats->F)))
if (!se)
return;
PN(se->exec_start);
PN(se->vruntime);
PN(se->sum_exec_runtime);
if (schedstat_enabled()) {
struct sched_statistics *stats;
stats = __schedstats_from_se(se);
PN_SCHEDSTAT(wait_start);
PN_SCHEDSTAT(sleep_start);
PN_SCHEDSTAT(block_start);
PN_SCHEDSTAT(sleep_max);
PN_SCHEDSTAT(block_max);
PN_SCHEDSTAT(exec_max);
PN_SCHEDSTAT(slice_max);
PN_SCHEDSTAT(wait_max);
PN_SCHEDSTAT(wait_sum);
P_SCHEDSTAT(wait_count);
}
P(se->load.weight);
#ifdef CONFIG_SMP
P(se->avg.load_avg);
P(se->avg.util_avg);
P(se->avg.runnable_avg);
#endif
#undef PN_SCHEDSTAT
#undef PN
#undef P_SCHEDSTAT
#undef P
}
#endif
#ifdef CONFIG_CGROUP_SCHED
static DEFINE_SPINLOCK(sched_debug_lock);
static char group_path[PATH_MAX];
static void task_group_path(struct task_group *tg, char *path, int plen)
{
if (autogroup_path(tg, path, plen))
return;
cgroup_path(tg->css.cgroup, path, plen);
}
/*
* Only 1 SEQ_printf_task_group_path() caller can use the full length
* group_path[] for cgroup path. Other simultaneous callers will have
* to use a shorter stack buffer. A "..." suffix is appended at the end
* of the stack buffer so that it will show up in case the output length
* matches the given buffer size to indicate possible path name truncation.
*/
#define SEQ_printf_task_group_path(m, tg, fmt...) \
{ \
if (spin_trylock(&sched_debug_lock)) { \
task_group_path(tg, group_path, sizeof(group_path)); \
SEQ_printf(m, fmt, group_path); \
spin_unlock(&sched_debug_lock); \
} else { \
char buf[128]; \
char *bufend = buf + sizeof(buf) - 3; \
task_group_path(tg, buf, bufend - buf); \
strcpy(bufend - 1, "..."); \
SEQ_printf(m, fmt, buf); \
} \
}
#endif
static void
print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
{
if (task_current(rq, p))
SEQ_printf(m, ">R");
else
SEQ_printf(m, " %c", task_state_to_char(p));
SEQ_printf(m, " %15s %5d %9Ld.%06ld %c %9Ld.%06ld %c %9Ld.%06ld %9Ld.%06ld %9Ld %5d ",
p->comm, task_pid_nr(p),
SPLIT_NS(p->se.vruntime),
entity_eligible(cfs_rq_of(&p->se), &p->se) ? 'E' : 'N',
SPLIT_NS(p->se.deadline),
p->se.custom_slice ? 'S' : ' ',
SPLIT_NS(p->se.slice),
SPLIT_NS(p->se.sum_exec_runtime),
(long long)(p->nvcsw + p->nivcsw),
p->prio);
SEQ_printf(m, "%9lld.%06ld %9lld.%06ld %9lld.%06ld",
SPLIT_NS(schedstat_val_or_zero(p->stats.wait_sum)),
SPLIT_NS(schedstat_val_or_zero(p->stats.sum_sleep_runtime)),
SPLIT_NS(schedstat_val_or_zero(p->stats.sum_block_runtime)));
#ifdef CONFIG_NUMA_BALANCING
SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
#endif
#ifdef CONFIG_CGROUP_SCHED
SEQ_printf_task_group_path(m, task_group(p), " %s")
#endif
SEQ_printf(m, "\n");
}
static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu)
{
struct task_struct *g, *p;
SEQ_printf(m, "\n");
SEQ_printf(m, "runnable tasks:\n");
SEQ_printf(m, " S task PID vruntime eligible "
"deadline slice sum-exec switches "
"prio wait-time sum-sleep sum-block"
#ifdef CONFIG_NUMA_BALANCING
" node group-id"
#endif
#ifdef CONFIG_CGROUP_SCHED
" group-path"
#endif
"\n");
SEQ_printf(m, "-------------------------------------------------------"
"------------------------------------------------------"
"------------------------------------------------------"
#ifdef CONFIG_NUMA_BALANCING
"--------------"
#endif
#ifdef CONFIG_CGROUP_SCHED
"--------------"
#endif
"\n");
rcu_read_lock();
for_each_process_thread(g, p) {
if (task_cpu(p) != rq_cpu)
continue;
print_task(m, rq, p);
}
rcu_read_unlock();
}
void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
{
s64 left_vruntime = -1, min_vruntime, right_vruntime = -1, left_deadline = -1, spread;
struct sched_entity *last, *first, *root;
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
#ifdef CONFIG_FAIR_GROUP_SCHED
SEQ_printf(m, "\n");
SEQ_printf_task_group_path(m, cfs_rq->tg, "cfs_rq[%d]:%s\n", cpu);
#else
SEQ_printf(m, "\n");
SEQ_printf(m, "cfs_rq[%d]:\n", cpu);
#endif
raw_spin_rq_lock_irqsave(rq, flags);
root = __pick_root_entity(cfs_rq);
if (root)
left_vruntime = root->min_vruntime;
first = __pick_first_entity(cfs_rq);
if (first)
left_deadline = first->deadline;
last = __pick_last_entity(cfs_rq);
if (last)
right_vruntime = last->vruntime;
min_vruntime = cfs_rq->min_vruntime;
raw_spin_rq_unlock_irqrestore(rq, flags);
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "left_deadline",
SPLIT_NS(left_deadline));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "left_vruntime",
SPLIT_NS(left_vruntime));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime",
SPLIT_NS(min_vruntime));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "avg_vruntime",
SPLIT_NS(avg_vruntime(cfs_rq)));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "right_vruntime",
SPLIT_NS(right_vruntime));
spread = right_vruntime - left_vruntime;
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "spread", SPLIT_NS(spread));
SEQ_printf(m, " .%-30s: %d\n", "nr_queued", cfs_rq->nr_queued);
SEQ_printf(m, " .%-30s: %d\n", "h_nr_runnable", cfs_rq->h_nr_runnable);
SEQ_printf(m, " .%-30s: %d\n", "h_nr_queued", cfs_rq->h_nr_queued);
SEQ_printf(m, " .%-30s: %d\n", "h_nr_idle", cfs_rq->h_nr_idle);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_SMP
SEQ_printf(m, " .%-30s: %lu\n", "load_avg",
cfs_rq->avg.load_avg);
SEQ_printf(m, " .%-30s: %lu\n", "runnable_avg",
cfs_rq->avg.runnable_avg);
SEQ_printf(m, " .%-30s: %lu\n", "util_avg",
cfs_rq->avg.util_avg);
SEQ_printf(m, " .%-30s: %u\n", "util_est",
cfs_rq->avg.util_est);
SEQ_printf(m, " .%-30s: %ld\n", "removed.load_avg",
cfs_rq->removed.load_avg);
SEQ_printf(m, " .%-30s: %ld\n", "removed.util_avg",
cfs_rq->removed.util_avg);
SEQ_printf(m, " .%-30s: %ld\n", "removed.runnable_avg",
cfs_rq->removed.runnable_avg);
#ifdef CONFIG_FAIR_GROUP_SCHED
SEQ_printf(m, " .%-30s: %lu\n", "tg_load_avg_contrib",
cfs_rq->tg_load_avg_contrib);
SEQ_printf(m, " .%-30s: %ld\n", "tg_load_avg",
atomic_long_read(&cfs_rq->tg->load_avg));
#endif
#endif
#ifdef CONFIG_CFS_BANDWIDTH
SEQ_printf(m, " .%-30s: %d\n", "throttled",
cfs_rq->throttled);
SEQ_printf(m, " .%-30s: %d\n", "throttle_count",
cfs_rq->throttle_count);
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
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, "\n");
SEQ_printf_task_group_path(m, rt_rq->tg, "rt_rq[%d]:%s\n", cpu);
#else
SEQ_printf(m, "\n");
SEQ_printf(m, "rt_rq[%d]:\n", cpu);
#endif
#define P(x) \
SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
#define PU(x) \
SEQ_printf(m, " .%-30s: %lu\n", #x, (unsigned long)(rt_rq->x))
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rt_rq->x))
PU(rt_nr_running);
#ifdef CONFIG_RT_GROUP_SCHED
P(rt_throttled);
PN(rt_time);
PN(rt_runtime);
#endif
#undef PN
#undef PU
#undef P
}
void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
{
struct dl_bw *dl_bw;
SEQ_printf(m, "\n");
SEQ_printf(m, "dl_rq[%d]:\n", cpu);
#define PU(x) \
SEQ_printf(m, " .%-30s: %lu\n", #x, (unsigned long)(dl_rq->x))
PU(dl_nr_running);
#ifdef CONFIG_SMP
dl_bw = &cpu_rq(cpu)->rd->dl_bw;
#else
dl_bw = &dl_rq->dl_bw;
#endif
SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->bw", dl_bw->bw);
SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->total_bw", dl_bw->total_bw);
#undef PU
}
static void print_cpu(struct seq_file *m, int cpu)
{
struct rq *rq = cpu_rq(cpu);
#ifdef CONFIG_X86
{
unsigned int freq = cpu_khz ? : 1;
SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
cpu, freq / 1000, (freq % 1000));
}
#else
SEQ_printf(m, "cpu#%d\n", cpu);
#endif
#define P(x) \
do { \
if (sizeof(rq->x) == 4) \
SEQ_printf(m, " .%-30s: %d\n", #x, (int)(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);
P(nr_switches);
P(nr_uninterruptible);
PN(next_balance);
SEQ_printf(m, " .%-30s: %ld\n", "curr->pid", (long)(task_pid_nr(rq->curr)));
PN(clock);
PN(clock_task);
#undef P
#undef PN
#ifdef CONFIG_SMP
#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
P64(avg_idle);
P64(max_idle_balance_cost);
#undef P64
#endif
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, schedstat_val(rq->n));
if (schedstat_enabled()) {
P(yld_count);
P(sched_count);
P(sched_goidle);
P(ttwu_count);
P(ttwu_local);
}
#undef P
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);
print_dl_stats(m, cpu);
print_rq(m, rq, cpu);
SEQ_printf(m, "\n");
}
static const char *sched_tunable_scaling_names[] = {
"none",
"logarithmic",
"linear"
};
static void sched_debug_header(struct seq_file *m)
{
u64 ktime, sched_clk, cpu_clk;
unsigned long flags;
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: v0.11, %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_base_slice);
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]);
SEQ_printf(m, "\n");
}
static int sched_debug_show(struct seq_file *m, void *v)
{
int cpu = (unsigned long)(v - 2);
if (cpu != -1)
print_cpu(m, cpu);
else
sched_debug_header(m);
return 0;
}
void sysrq_sched_debug_show(void)
{
int cpu;
sched_debug_header(NULL);
for_each_online_cpu(cpu) {
/*
* Need to reset softlockup watchdogs on all CPUs, because
* another CPU might be blocked waiting for us to process
* an IPI or stop_machine.
*/
touch_nmi_watchdog();
touch_all_softlockup_watchdogs();
print_cpu(NULL, cpu);
}
}
/*
* This iterator needs some explanation.
* It returns 1 for the header position.
* This means 2 is CPU 0.
* In a hotplugged system some CPUs, including CPU 0, may be missing so we have
* to use cpumask_* to iterate over the CPUs.
*/
static void *sched_debug_start(struct seq_file *file, loff_t *offset)
{
unsigned long n = *offset;
if (n == 0)
return (void *) 1;
n--;
if (n > 0)
n = cpumask_next(n - 1, cpu_online_mask);
else
n = cpumask_first(cpu_online_mask);
*offset = n + 1;
if (n < nr_cpu_ids)
return (void *)(unsigned long)(n + 2);
return NULL;
}
static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
{
(*offset)++;
return sched_debug_start(file, offset);
}
static void sched_debug_stop(struct seq_file *file, void *data)
{
}
static const struct seq_operations sched_debug_sops = {
.start = sched_debug_start,
.next = sched_debug_next,
.stop = sched_debug_stop,
.show = sched_debug_show,
};
#define __PS(S, F) SEQ_printf(m, "%-45s:%21Ld\n", S, (long long)(F))
#define __P(F) __PS(#F, F)
#define P(F) __PS(#F, p->F)
#define PM(F, M) __PS(#F, p->F & (M))
#define __PSN(S, F) SEQ_printf(m, "%-45s:%14Ld.%06ld\n", S, SPLIT_NS((long long)(F)))
#define __PN(F) __PSN(#F, F)
#define PN(F) __PSN(#F, p->F)
#ifdef CONFIG_NUMA_BALANCING
void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
unsigned long tpf, unsigned long gsf, unsigned long gpf)
{
SEQ_printf(m, "numa_faults node=%d ", node);
SEQ_printf(m, "task_private=%lu task_shared=%lu ", tpf, tsf);
SEQ_printf(m, "group_private=%lu group_shared=%lu\n", gpf, gsf);
}
#endif
static void sched_show_numa(struct task_struct *p, struct seq_file *m)
{
#ifdef CONFIG_NUMA_BALANCING
if (p->mm)
P(mm->numa_scan_seq);
P(numa_pages_migrated);
P(numa_preferred_nid);
P(total_numa_faults);
SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
task_node(p), task_numa_group_id(p));
show_numa_stats(p, m);
#endif
}
void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
struct seq_file *m)
{
unsigned long nr_switches;
SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns),
get_nr_threads(p));
SEQ_printf(m,
"---------------------------------------------------------"
"----------\n");
#define P_SCHEDSTAT(F) __PS(#F, schedstat_val(p->stats.F))
#define PN_SCHEDSTAT(F) __PSN(#F, schedstat_val(p->stats.F))
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
nr_switches = p->nvcsw + p->nivcsw;
P(se.nr_migrations);
if (schedstat_enabled()) {
u64 avg_atom, avg_per_cpu;
PN_SCHEDSTAT(sum_sleep_runtime);
PN_SCHEDSTAT(sum_block_runtime);
PN_SCHEDSTAT(wait_start);
PN_SCHEDSTAT(sleep_start);
PN_SCHEDSTAT(block_start);
PN_SCHEDSTAT(sleep_max);
PN_SCHEDSTAT(block_max);
PN_SCHEDSTAT(exec_max);
PN_SCHEDSTAT(slice_max);
PN_SCHEDSTAT(wait_max);
PN_SCHEDSTAT(wait_sum);
P_SCHEDSTAT(wait_count);
PN_SCHEDSTAT(iowait_sum);
P_SCHEDSTAT(iowait_count);
P_SCHEDSTAT(nr_migrations_cold);
P_SCHEDSTAT(nr_failed_migrations_affine);
P_SCHEDSTAT(nr_failed_migrations_running);
P_SCHEDSTAT(nr_failed_migrations_hot);
P_SCHEDSTAT(nr_forced_migrations);
P_SCHEDSTAT(nr_wakeups);
P_SCHEDSTAT(nr_wakeups_sync);
P_SCHEDSTAT(nr_wakeups_migrate);
P_SCHEDSTAT(nr_wakeups_local);
P_SCHEDSTAT(nr_wakeups_remote);
P_SCHEDSTAT(nr_wakeups_affine);
P_SCHEDSTAT(nr_wakeups_affine_attempts);
P_SCHEDSTAT(nr_wakeups_passive);
P_SCHEDSTAT(nr_wakeups_idle);
avg_atom = p->se.sum_exec_runtime;
if (nr_switches)
avg_atom = div64_ul(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);
#ifdef CONFIG_SCHED_CORE
PN_SCHEDSTAT(core_forceidle_sum);
#endif
}
__P(nr_switches);
__PS("nr_voluntary_switches", p->nvcsw);
__PS("nr_involuntary_switches", p->nivcsw);
P(se.load.weight);
#ifdef CONFIG_SMP
P(se.avg.load_sum);
P(se.avg.runnable_sum);
P(se.avg.util_sum);
P(se.avg.load_avg);
P(se.avg.runnable_avg);
P(se.avg.util_avg);
P(se.avg.last_update_time);
PM(se.avg.util_est, ~UTIL_AVG_UNCHANGED);
#endif
#ifdef CONFIG_UCLAMP_TASK
__PS("uclamp.min", p->uclamp_req[UCLAMP_MIN].value);
__PS("uclamp.max", p->uclamp_req[UCLAMP_MAX].value);
__PS("effective uclamp.min", uclamp_eff_value(p, UCLAMP_MIN));
__PS("effective uclamp.max", uclamp_eff_value(p, UCLAMP_MAX));
#endif
P(policy);
P(prio);
if (task_has_dl_policy(p)) {
P(dl.runtime);
P(dl.deadline);
} else if (fair_policy(p->policy)) {
P(se.slice);
}
#ifdef CONFIG_SCHED_CLASS_EXT
__PS("ext.enabled", task_on_scx(p));
#endif
#undef PN_SCHEDSTAT
#undef P_SCHEDSTAT
{
unsigned int this_cpu = raw_smp_processor_id();
u64 t0, t1;
t0 = cpu_clock(this_cpu);
t1 = cpu_clock(this_cpu);
__PS("clock-delta", t1-t0);
}
sched_show_numa(p, m);
}
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
memset(&p->stats, 0, sizeof(p->stats));
#endif
}
void resched_latency_warn(int cpu, u64 latency)
{
static DEFINE_RATELIMIT_STATE(latency_check_ratelimit, 60 * 60 * HZ, 1);
if (likely(!__ratelimit(&latency_check_ratelimit)))
return;
pr_err("sched: CPU %d need_resched set for > %llu ns (%d ticks) without schedule\n",
cpu, latency, cpu_rq(cpu)->ticks_without_resched);
dump_stack();
}