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| author | Peter Zijlstra <peterz@infradead.org> | 2021-05-04 23:43:32 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-05-12 12:43:25 +0300 |
| commit | e4042ad492357fa995921376462b04a025dd53b6 (patch) | |
| tree | 17a443a2b9b1be2276664e026f63e0c6b97127dd /kernel/delayacct.c | |
| parent | eee4d9fee2544389e5ce5697ed92db67c86d7a9f (diff) | |
| download | linux-e4042ad492357fa995921376462b04a025dd53b6.tar.xz | |
delayacct: Default disabled
Assuming this stuff isn't actually used much; disable it by default
and avoid allocating and tracking the task_delay_info structure.
taskstats is changed to still report the regular sched and sched_info
and only skip the missing task_delay_info fields instead of not
reporting anything.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210505111525.308018373@infradead.org
Diffstat (limited to 'kernel/delayacct.c')
| -rw-r--r-- | kernel/delayacct.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 63012fd39ae2..3f086903b295 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -14,23 +14,23 @@ #include <linux/delayacct.h> #include <linux/module.h> -DEFINE_STATIC_KEY_TRUE(delayacct_key); -int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ +DEFINE_STATIC_KEY_FALSE(delayacct_key); +int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; -static int __init delayacct_setup_disable(char *str) +static int __init delayacct_setup_enable(char *str) { - delayacct_on = 0; + delayacct_on = 1; return 1; } -__setup("nodelayacct", delayacct_setup_disable); +__setup("delayacct", delayacct_setup_enable); void delayacct_init(void) { delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); delayacct_tsk_init(&init_task); - if (!delayacct_on) - static_branch_disable(&delayacct_key); + if (delayacct_on) + static_branch_enable(&delayacct_key); } void __delayacct_tsk_init(struct task_struct *tsk) @@ -83,7 +83,7 @@ void __delayacct_blkio_end(struct task_struct *p) delayacct_end(&delays->lock, &delays->blkio_start, total, count); } -int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) +int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) { u64 utime, stime, stimescaled, utimescaled; unsigned long long t2, t3; @@ -118,6 +118,9 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->cpu_run_virtual_total = (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; + if (!tsk->delays) + return 0; + /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ raw_spin_lock_irqsave(&tsk->delays->lock, flags); |