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| author | Peter Zijlstra <peterz@infradead.org> | 2021-05-10 14:01:00 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-05-12 11:43:25 +0200 |
| commit | 0cd7c741f01de13dc1eecf22557593b3514639bb (patch) | |
| tree | 9d1031e2a5e08dc9d45a6670f4d8e6171be8864c /kernel/delayacct.c | |
| parent | e4042ad492357fa995921376462b04a025dd53b6 (diff) | |
| download | linux-0cd7c741f01de13dc1eecf22557593b3514639bb.tar.bz2 | |
delayacct: Add sysctl to enable at runtime
Just like sched_schedstats, allow runtime enabling (and disabling) of
delayacct. This is useful if one forgot to add the delayacct boot time
option.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YJkhebGJAywaZowX@hirez.programming.kicks-ass.net
Diffstat (limited to 'kernel/delayacct.c')
| -rw-r--r-- | kernel/delayacct.c | 36 |
1 files changed, 34 insertions, 2 deletions
diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 3f086903b295..51530d5b15a8 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -18,6 +18,17 @@ DEFINE_STATIC_KEY_FALSE(delayacct_key); int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; +static void set_delayacct(bool enabled) +{ + if (enabled) { + static_branch_enable(&delayacct_key); + delayacct_on = 1; + } else { + delayacct_on = 0; + static_branch_disable(&delayacct_key); + } +} + static int __init delayacct_setup_enable(char *str) { delayacct_on = 1; @@ -29,9 +40,30 @@ 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_enable(&delayacct_key); + set_delayacct(delayacct_on); +} + +#ifdef CONFIG_PROC_SYSCTL +int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + int state = delayacct_on; + struct ctl_table t; + int err; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + t = *table; + t.data = &state; + err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + if (write) + set_delayacct(state); + return err; } +#endif void __delayacct_tsk_init(struct task_struct *tsk) { |