From af2350bd12096dfd04e1090b90bfecea1f75f84e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 15 Jul 2013 16:35:55 +0200 Subject: [PATCH] vtime: Always debug check snapshot source _before_ updating it 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 Cc: Steven Rostedt Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Li Zhong Cc: Mike Galbraith Cc: Kevin Hilman --- kernel/sched/cputime.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index e9e742ed7280..c1d7493825ae 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) { 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); } -- 2.39.5