diff options
| author | Frederic Weisbecker <frederic@kernel.org> | 2021-07-26 14:55:10 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-15 09:47:26 +0200 |
| commit | c322a963d522e9a4273e18c9d7bd6fd40a25160f (patch) | |
| tree | 40056bbe37d1ee438026a5070a25250bdc97565e /kernel/time | |
| parent | 28996dbb8a74e0ffc8715f3fd463efafa0947db1 (diff) | |
posix-cpu-timers: Force next expiration recalc after itimer reset
[ Upstream commit 406dd42bd1ba0c01babf9cde169bb319e52f6147 ]
When an itimer deactivates a previously armed expiration, it simply doesn't
do anything. As a result the process wide cputime counter keeps running and
the tick dependency stays set until it reaches the old ghost expiration
value.
This can be reproduced with the following snippet:
void trigger_process_counter(void)
{
struct itimerval n = {};
n.it_value.tv_sec = 100;
setitimer(ITIMER_VIRTUAL, &n, NULL);
n.it_value.tv_sec = 0;
setitimer(ITIMER_VIRTUAL, &n, NULL);
}
Fix this with resetting the relevant base expiration. This is similar to
disarming a timer.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210726125513.271824-4-frederic@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/posix-cpu-timers.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index eacb0ca30193..30e061b210b7 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1201,8 +1201,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, } } - if (!*newval) - return; *newval += now; } |