From e6d5bf3e321ca664d12eb00ceb40bd58987ce8a1 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 16 Oct 2019 04:56:49 +0200 Subject: sched/cputime: Add vtime guest task state Record guest as a VTIME state instead of guessing it from VTIME_SYS and PF_VCPU. 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/20191016025700.31277-4-frederic@kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/cputime.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 2e885e870aa1..34086afc3518 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -733,7 +733,7 @@ static void __vtime_account_kernel(struct task_struct *tsk, struct vtime *vtime) { /* We might have scheduled out from guest path */ - if (tsk->flags & PF_VCPU) + if (vtime->state == VTIME_GUEST) vtime_account_guest(tsk, vtime); else vtime_account_system(tsk, vtime); @@ -788,6 +788,7 @@ void vtime_guest_enter(struct task_struct *tsk) write_seqcount_begin(&vtime->seqcount); vtime_account_system(tsk, vtime); tsk->flags |= PF_VCPU; + vtime->state = VTIME_GUEST; write_seqcount_end(&vtime->seqcount); } EXPORT_SYMBOL_GPL(vtime_guest_enter); @@ -799,6 +800,7 @@ void vtime_guest_exit(struct task_struct *tsk) write_seqcount_begin(&vtime->seqcount); vtime_account_guest(tsk, vtime); tsk->flags &= ~PF_VCPU; + vtime->state = VTIME_SYS; write_seqcount_end(&vtime->seqcount); } EXPORT_SYMBOL_GPL(vtime_guest_exit); @@ -826,6 +828,8 @@ void vtime_task_switch_generic(struct task_struct *prev) write_seqcount_begin(&vtime->seqcount); if (is_idle_task(current)) vtime->state = VTIME_IDLE; + else if (current->flags & PF_VCPU) + vtime->state = VTIME_GUEST; else vtime->state = VTIME_SYS; vtime->starttime = sched_clock(); @@ -860,7 +864,7 @@ u64 task_gtime(struct task_struct *t) seq = read_seqcount_begin(&vtime->seqcount); gtime = t->gtime; - if (vtime->state == VTIME_SYS && t->flags & PF_VCPU) + if (vtime->state == VTIME_GUEST) gtime += vtime->gtime + vtime_delta(vtime); } while (read_seqcount_retry(&vtime->seqcount, seq)); @@ -898,13 +902,13 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime) delta = vtime_delta(vtime); /* - * Task runs either in user or kernel space, add pending nohz time to - * the right place. + * Task runs either in user (including guest) or kernel space, + * add pending nohz time to the right place. */ - if (vtime->state == VTIME_USER || t->flags & PF_VCPU) - *utime += vtime->utime + delta; - else if (vtime->state == VTIME_SYS) + if (vtime->state == VTIME_SYS) *stime += vtime->stime + delta; + else + *utime += vtime->utime + delta; } while (read_seqcount_retry(&vtime->seqcount, seq)); } #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ -- cgit v1.2.3-59-g8ed1b