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author | Frederic Weisbecker <frederic@kernel.org> | 2021-07-26 14:55:10 +0200 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2021-08-10 17:09:59 +0200 |
commit | 406dd42bd1ba0c01babf9cde169bb319e52f6147 (patch) | |
tree | 44d288849968f2fa60e43487f3e5618bce3707bc /kernel/time | |
parent | 175cc3ab28e3509ddee8de4f164b563d99daa570 (diff) | |
download | linux-406dd42bd1ba0c01babf9cde169bb319e52f6147.tar.gz linux-406dd42bd1ba0c01babf9cde169bb319e52f6147.tar.bz2 linux-406dd42bd1ba0c01babf9cde169bb319e52f6147.zip |
posix-cpu-timers: Force next expiration recalc after itimer reset
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
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 61c78b62fe6a..5c71322b45c7 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1379,8 +1379,6 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, } } - if (!*newval) - return; *newval += now; } |