Patch "sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime" has been added to the 4.12-stable tree

Patch "sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sched-cputime-always-set-tsk-vtime_snap_whence-after-accounting-vtime.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 9fa57cf5a5c4aed1e45879b335fe433048709327 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Thu, 29 Jun 2017 19:15:08 +0200
Subject: sched/cputime: Always set tsk->vtime_snap_whence after accounting vtime

From: Frederic Weisbecker <fweisbec@gmail.com>

commit 9fa57cf5a5c4aed1e45879b335fe433048709327 upstream.

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>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -736,9 +736,9 @@ void vtime_user_enter(struct task_struct
 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);
 }
 


Patches currently in stable-queue which might be from fweisbec@gmail.com are

queue-4.12/sched-cputime-rename-vtime-fields.patch
queue-4.12/vtime-sched-cputime-remove-vtime_account_user.patch
queue-4.12/sched-cputime-accumulate-vtime-on-top-of-nsec-clocksource.patch
queue-4.12/sched-cputime-move-the-vtime-task-fields-to-their-own-struct.patch
queue-4.12/sched-cputime-always-set-tsk-vtime_snap_whence-after-accounting-vtime.patch