cputime: Consolidate vtime handling on context switch

The archs that implement virtual cputime accounting all
flush the cputime of a task when it gets descheduled
and sometimes set up some ground initialization for the
next task to account its cputime.

These archs all put their own hooks in their context
switch callbacks and handle the off-case themselves.

Consolidate this by creating a new account_switch_vtime()
callback called in generic code right after a context switch
and that these archs must implement to flush the prev task
cputime and initialize the next task cputime related state.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ae3bcaa3afbf..78d9c965433a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1796,6 +1796,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
 	 *		Manfred Spraul <manfred@colorfullife.com>
 	 */
 	prev_state = prev->state;
+	account_switch_vtime(prev);
 	finish_arch_switch(prev);
 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
 	local_irq_disable();