[patch 13/44] posix-cpu-timers: Sample directly in timer check

Thomas Gleixner
2019-08-19T15:48:21Z

The thread group accounting is active, otherwise the expiry function would
not be running. Sample the thread group time directly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -914,16 +914,17 @@ static void check_process_timers(struct
if (!READ_ONCE(tsk->signal->cputimer.running))
return;

- /*
+ /*
* Signify that a thread is checking for process timers.
* Write access to this field is protected by the sighand lock.
*/
sig->cputimer.checking_timer = true;

/*
- * Collect the current process totals.
+ * Collect the current process totals. Group accounting is active
+ * so the sample can be taken directly.
*/
- thread_group_cputimer(tsk, &cputime);
+ sample_cputime_atomic(&cputime, &sig->cputimer.cputime_atomic);
utime = cputime.utime;
ptime = utime + cputime.stime;
sum_sched_runtime = cputime.sum_exec_runtime;