[PATCH 20/23] vtime: Always debug check snapshot source _before_ updating it

From: Frederic Weisbecker
Date: Wed Jul 31 2013 - 20:32:26 EST

The vtime delta update performed by get_vtime_delta() always check
that the source of the snapshot is valid.

Meanhile the snapshot updaters that rely on get_vtime_delta() also
set the new snapshot origin. But some of them do this right before
the call to get_vtime_delta(), making its debug check useless.

This is easily fixable by moving the snapshot origin update after
the call to get_vtime_delta(). The order doesn't matter there.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Kevin Hilman <khilman@xxxxxxxxxx>
kernel/sched/cputime.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index e9e742e..c1d7493 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -660,9 +660,9 @@ void vtime_account_system(struct task_struct *tsk)
void vtime_gen_account_irq_exit(struct task_struct *tsk)
+ __vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
- __vtime_account_system(tsk);

@@ -680,8 +680,8 @@ void vtime_account_user(struct task_struct *tsk)
void vtime_user_enter(struct task_struct *tsk)
- tsk->vtime_snap_whence = VTIME_USER;
+ tsk->vtime_snap_whence = VTIME_USER;


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