sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime
authorFrederic Weisbecker <fweisbec@gmail.com>
Thu, 29 Jun 2017 17:15:08 +0000 (19:15 +0200)
committerIngo Molnar <mingo@kernel.org>
Wed, 5 Jul 2017 07:54:14 +0000 (09:54 +0200)
Even though it doesn't have functional consequences, setting
the task's new context state after we actually accounted the pending
vtime from the old context state makes more sense from a review
perspective.

vtime_user_exit() is the only function that doesn't follow that rule
and that can bug the reviewer for a little while until he realizes there
is no reason for this special case.

Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1498756511-11714-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/sched/cputime.c

index 5adc896d0f6444211777fdff9b3fc4701b150c15..ab68927e8e94a8fc0551a3319788fea36ee4c0fe 100644 (file)
@@ -736,9 +736,9 @@ void vtime_user_enter(struct task_struct *tsk)
 void vtime_user_exit(struct task_struct *tsk)
 {
        write_seqcount_begin(&tsk->vtime_seqcount);
-       tsk->vtime_snap_whence = VTIME_SYS;
        if (vtime_delta(tsk))
                account_user_time(tsk, get_vtime_delta(tsk));
+       tsk->vtime_snap_whence = VTIME_SYS;
        write_seqcount_end(&tsk->vtime_seqcount);
 }