From 14faf6fcac4ba33f8fd8d9b2d0278010a9eb1742 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 16 Oct 2019 04:56:48 +0200 Subject: sched/cputime: Add vtime idle task state Record idle as a VTIME state instead of guessing it from VTIME_SYS and is_idle_task(). This is going to simplify the cputime read side especially as its state machine is going to further expand in order to fully support kcpustat on nohz_full. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Cc: Jacek Anaszewski Cc: Linus Torvalds Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J . Wysocki Cc: Rik van Riel Cc: Thomas Gleixner Cc: Viresh Kumar Cc: Wanpeng Li Cc: Yauheni Kaliuta Link: https://lkml.kernel.org/r/20191016025700.31277-3-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/cputime.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 40f581692254..2e885e870aa1 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -813,7 +813,7 @@ void vtime_task_switch_generic(struct task_struct *prev) struct vtime *vtime = &prev->vtime; write_seqcount_begin(&vtime->seqcount); - if (is_idle_task(prev)) + if (vtime->state == VTIME_IDLE) vtime_account_idle(prev); else __vtime_account_kernel(prev, vtime); @@ -824,7 +824,10 @@ void vtime_task_switch_generic(struct task_struct *prev) vtime = ¤t->vtime; write_seqcount_begin(&vtime->seqcount); - vtime->state = VTIME_SYS; + if (is_idle_task(current)) + vtime->state = VTIME_IDLE; + else + vtime->state = VTIME_SYS; vtime->starttime = sched_clock(); vtime->cpu = smp_processor_id(); write_seqcount_end(&vtime->seqcount); @@ -837,7 +840,7 @@ void vtime_init_idle(struct task_struct *t, int cpu) local_irq_save(flags); write_seqcount_begin(&vtime->seqcount); - vtime->state = VTIME_SYS; + vtime->state = VTIME_IDLE; vtime->starttime = sched_clock(); vtime->cpu = cpu; write_seqcount_end(&vtime->seqcount); @@ -888,8 +891,8 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime) *utime = t->utime; *stime = t->stime; - /* Task is sleeping, nothing to add */ - if (vtime->state == VTIME_INACTIVE || is_idle_task(t)) + /* Task is sleeping or idle, nothing to add */ + if (vtime->state < VTIME_SYS) continue; delta = vtime_delta(vtime); -- cgit v1.2.3