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From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Wanpeng Li <wanpengli@tencent.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Yauheni Kaliuta <yauheni.kaliuta@redhat.com>,
	Ingo Molnar <mingo@kernel.org>, Rik van Riel <riel@redhat.com>
Subject: [PATCH 07/25] sched/cputime: Add vtime guest task state
Date: Wed, 14 Nov 2018 03:45:51 +0100	[thread overview]
Message-ID: <1542163569-20047-8-git-send-email-frederic@kernel.org> (raw)
In-Reply-To: <1542163569-20047-1-git-send-email-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@redhat.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 6d13938..d458d65 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -271,6 +271,8 @@ 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 a9f42cc..f64afd7 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -732,7 +732,7 @@ 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);
@@ -787,6 +787,7 @@ 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);
@@ -798,6 +799,7 @@ 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);
@@ -825,6 +827,8 @@ 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();
@@ -859,7 +863,7 @@ 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));
@@ -897,13 +901,13 @@ 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 */
-- 
2.7.4


  parent reply	other threads:[~2018-11-14  2:46 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-14  2:45 [PATCH 00/25] sched/nohz: Make kcpustat vtime aware (Fix kcpustat on nohz_full) Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 01/25] sched/vtime: Fix guest/system mis-accounting on task switch Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 02/25] sched/vtime: Protect idle accounting under vtime seqcount Frederic Weisbecker
2018-11-20 13:19   ` Peter Zijlstra
2018-11-14  2:45 ` [PATCH 03/25] vtime: Rename vtime_account_system() to vtime_account_kernel() Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 04/25] vtime: Spare a seqcount lock/unlock cycle on context switch Frederic Weisbecker
2018-11-20 13:25   ` Peter Zijlstra
2019-09-25 14:42     ` Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 05/25] sched/vtime: Record CPU under seqcount for kcpustat needs Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 06/25] sched/cputime: Add vtime idle task state Frederic Weisbecker
2018-11-14  2:45 ` Frederic Weisbecker [this message]
2018-11-14  2:45 ` [PATCH 08/25] vtime: Exit vtime before exit_notify() Frederic Weisbecker
2018-11-20 13:54   ` Peter Zijlstra
2018-11-14  2:45 ` [PATCH 09/25] kcpustat: Track running task following vtime sequences Frederic Weisbecker
2018-11-20 13:58   ` Peter Zijlstra
2018-11-14  2:45 ` [PATCH 10/25] context_tracking: Remove context_tracking_active() Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 11/25] context_tracking: s/context_tracking_is_enabled/context_tracking_enabled() Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 12/25] context_tracking: Rename context_tracking_is_cpu_enabled() to context_tracking_enabled_this_cpu() Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 13/25] context_tracking: Introduce context_tracking_enabled_cpu() Frederic Weisbecker
2018-11-20 14:02   ` Peter Zijlstra
2018-11-14  2:45 ` [PATCH 14/25] sched/vtime: Rename vtime_accounting_cpu_enabled() to vtime_accounting_enabled_this_cpu() Frederic Weisbecker
2018-11-14  2:45 ` [PATCH 15/25] sched/vtime: Introduce vtime_accounting_enabled_cpu() Frederic Weisbecker
2018-11-20 14:04   ` Peter Zijlstra
2018-11-14  2:46 ` [PATCH 16/25] sched/cputime: Allow to pass cputime index on user/guest accounting Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 17/25] sched/cputime: Standardize the kcpustat index based accounting functions Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 18/25] vtime: Track nice-ness on top of context switch Frederic Weisbecker
2018-11-20 14:09   ` Peter Zijlstra
2018-11-14  2:46 ` [PATCH 19/25] sched/vite: Handle nice updates under vtime Frederic Weisbecker
2018-11-20 14:17   ` Peter Zijlstra
2018-11-26 15:53     ` Frederic Weisbecker
2018-11-26 16:11       ` Peter Zijlstra
2018-11-26 18:41         ` Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 20/25] sched/kcpustat: Introduce vtime-aware kcpustat accessor Frederic Weisbecker
2018-11-20 14:23   ` Peter Zijlstra
2018-11-20 22:40     ` Frederic Weisbecker
2018-11-21  8:18       ` Peter Zijlstra
2018-11-21  8:35         ` Peter Zijlstra
2018-11-21 16:33         ` Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 21/25] procfs: Use vtime aware " Frederic Weisbecker
2018-11-20 14:24   ` Peter Zijlstra
2018-11-20 22:31     ` Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 22/25] cpufreq: " Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 23/25] leds: Use vtime aware kcpustat accessors Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 24/25] rackmeter: " Frederic Weisbecker
2018-11-14  2:46 ` [PATCH 25/25] sched/vtime: Clarify vtime_task_switch() argument layout Frederic Weisbecker

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