diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2019-08-21 21:08:51 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-08-28 11:50:26 +0200 |
| commit | 19298fbf453c90a6cf72288155f80c6f55e9139d (patch) | |
| tree | c1c35ecaa0f7112b18ab202889d56a9f358e24c9 /kernel/time | |
| parent | e5a8b65b4cb2fe024b83bdec0424269949cc0a27 (diff) | |
posix-cpu-timers: Provide quick sample function for itimer
get_itimer() needs a sample of the current thread group cputime. It invokes
thread_group_cputimer() - which is a misnomer. That function also starts
eventually the group cputime accouting which is bogus because the
accounting is already active when a timer is armed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.599658199@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/posix-cpu-timers.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 4426a0f9c470..c22b6b604a95 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -232,6 +232,27 @@ static inline void sample_cputime_atomic(struct task_cputime *times, times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime); } +/** + * thread_group_sample_cputime - Sample cputime for a given task + * @tsk: Task for which cputime needs to be started + * @iimes: Storage for time samples + * + * Called from sys_getitimer() to calculate the expiry time of an active + * timer. That means group cputime accounting is already active. Called + * with task sighand lock held. + * + * Updates @times with an uptodate sample of the thread group cputimes. + */ +void thread_group_sample_cputime(struct task_struct *tsk, + struct task_cputime *times) +{ + struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; + + WARN_ON_ONCE(!cputimer->running); + + sample_cputime_atomic(times, &cputimer->cputime_atomic); +} + void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) { struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; |