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vtime: Always debug check snapshot source _before_ updating it

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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@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
This commit is contained in:
Frederic Weisbecker 2013-07-15 16:35:55 +02:00
parent b854fafa4e
commit af2350bd12
1 changed files with 2 additions and 2 deletions
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4
kernel/sched/cputime.c
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@ -660,9 +660,9 @@ void vtime_account_system(struct task_struct *tsk)
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
__vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
__vtime_account_system(tsk);
write_sequnlock(&tsk->vtime_seqlock);
}
@ -680,8 +680,8 @@ void vtime_account_user(struct task_struct *tsk)
void vtime_user_enter(struct task_struct *tsk)
{
write_seqlock(&tsk->vtime_seqlock);
tsk->vtime_snap_whence = VTIME_USER;
__vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
write_sequnlock(&tsk->vtime_seqlock);
}