[tip: timers/core] itimers: Use quick sample function

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     a34360d42434bbf28c0f375444c52c154ae3e6cf
Gitweb:        https://git.kernel.org/tip/a34360d42434bbf28c0f375444c52c154ae3e6cf
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Wed, 21 Aug 2019 21:08:52 +02:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 28 Aug 2019 11:50:26 +02:00

itimers: Use quick sample function

get_itimer() locks sighand lock and checks whether the timer is already
expired. If it is not expired then the thread group cputime accounting is
already enabled. Use the sampling function not the one which is meant for
starting a timer.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190821192919.689713638@xxxxxxxxxxxxx

---
 kernel/time/itimer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 9d26fd4..ae04bc2 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -58,7 +58,7 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 		struct task_cputime cputime;
 		u64 t;
 
-		thread_group_cputimer(tsk, &cputime);
+		thread_group_sample_cputime(tsk, &cputime);
 		if (clock_id == CPUCLOCK_PROF)
 			t = cputime.utime + cputime.stime;
 		else