From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Wanpeng Li <wanpengli@tencent.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Yauheni Kaliuta <yauheni.kaliuta@redhat.com>,
Ingo Molnar <mingo@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Pavel Machek <pavel@ucw.cz>
Subject: [PATCH 03/14] sched/cputime: Add vtime guest task state
Date: Wed, 16 Oct 2019 04:56:49 +0200 [thread overview]
Message-ID: <20191016025700.31277-4-frederic@kernel.org> (raw)
In-Reply-To: <20191016025700.31277-1-frederic@kernel.org>
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 <frederic@kernel.org>
Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched.h | 2 ++
kernel/sched/cputime.c | 18 +++++++++++-------
2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4ae19be2c126..988c4da00c31 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -255,6 +255,8 @@ enum vtime_state {
VTIME_SYS,
/* Task runs in userspace in a CPU with VTIME active: */
VTIME_USER,
+ /* Task runs as guests in a CPU with VTIME active: */
+ VTIME_GUEST,
};
struct vtime {
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 */
--
2.23.0
next prev parent reply other threads:[~2019-10-16 2:57 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 2:56 [PATCH 00/14] sched/nohz: Make kcpustat's CPUTIME_SYSTEM vtime aware v2 (Partially fix kcpustat on nohz_full) Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 01/14] sched/vtime: Record CPU under seqcount for kcpustat needs Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 02/14] sched/cputime: Add vtime idle task state Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` Frederic Weisbecker [this message]
2019-10-29 9:52 ` [tip: sched/core] sched/cputime: Add vtime guest " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 04/14] context_tracking: Remove context_tracking_active() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 05/14] context_tracking: s/context_tracking_is_enabled/context_tracking_enabled() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] context_tracking: Rename context_tracking_is_enabled() => context_tracking_enabled() tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 06/14] context_tracking: Rename context_tracking_is_cpu_enabled() to context_tracking_enabled_this_cpu() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 07/14] context_tracking: Introduce context_tracking_enabled_cpu() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 08/14] sched/vtime: Rename vtime_accounting_cpu_enabled() to vtime_accounting_enabled_this_cpu() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 09/14] sched/vtime: Introduce vtime_accounting_enabled_cpu() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 10/14] context_tracking: Check static key on context_tracking_enabled_*cpu() Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 11/14] sched/kcpustat: Introduce vtime-aware kcpustat accessor for CPUTIME_SYSTEM Frederic Weisbecker
2019-10-24 11:50 ` Peter Zijlstra
2019-10-25 1:25 ` Frederic Weisbecker
2019-10-25 2:03 ` [PATCH 11/14 v2] " Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 12/14] procfs: Use vtime aware kcpustat accessor to fetch CPUTIME_SYSTEM Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:56 ` [PATCH 13/14] cpufreq: " Frederic Weisbecker
2019-10-16 3:40 ` Viresh Kumar
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-16 2:57 ` [PATCH 14/14] leds: " Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " tip-bot2 for Frederic Weisbecker
2019-10-24 0:45 ` [GIT PULL] sched/nohz: Make kcpustat's CPUTIME_SYSTEM vtime aware Frederic Weisbecker
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