On task switch we must initialize the current cputime of the next task using the value of the previous task which got freshly updated.
But we are confusing that with doing the opposite, which should result in wrong cputime accounting. Cc: Benjamin Herrenschmidt <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Martin Schwidefsky <[email protected]> Cc: Tony Luck <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Stanislaw Gruszka <[email protected]> Cc: Wanpeng Li <[email protected]> Cc: Christian Borntraeger <[email protected]> Signed-off-by: Frederic Weisbecker <[email protected]> --- arch/ia64/kernel/time.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 71775b95..637e741 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -83,7 +83,7 @@ void arch_vtime_task_switch(struct task_struct *prev) struct thread_info *pi = task_thread_info(prev); struct thread_info *ni = task_thread_info(current); - pi->ac_stamp = ni->ac_stamp; + ni->ac_stamp = pi->ac_stamp; ni->ac_stime = ni->ac_utime = 0; } -- 2.7.4
