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 01/14] sched/vtime: Record CPU under seqcount for kcpustat needs
Date: Wed, 16 Oct 2019 04:56:47 +0200 [thread overview]
Message-ID: <20191016025700.31277-2-frederic@kernel.org> (raw)
In-Reply-To: <20191016025700.31277-1-frederic@kernel.org>
In order to compute the kcpustat delta on a nohz CPU, we'll need to
fetch the task running on that target. Checking that its vtime
state snapshot actually refers to the relevant target involves recording
that CPU under the seqcount locked on task switch.
This is a step toward making kcpustat moving forward on full nohz CPUs.
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 | 1 +
kernel/sched/cputime.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2c2e56bd8913..d5d07335a97b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -259,6 +259,7 @@ struct vtime {
seqcount_t seqcount;
unsigned long long starttime;
enum vtime_state state;
+ unsigned int cpu;
u64 utime;
u64 stime;
u64 gtime;
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index cef23c211f41..40f581692254 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -818,6 +818,7 @@ void vtime_task_switch_generic(struct task_struct *prev)
else
__vtime_account_kernel(prev, vtime);
vtime->state = VTIME_INACTIVE;
+ vtime->cpu = -1;
write_seqcount_end(&vtime->seqcount);
vtime = ¤t->vtime;
@@ -825,6 +826,7 @@ void vtime_task_switch_generic(struct task_struct *prev)
write_seqcount_begin(&vtime->seqcount);
vtime->state = VTIME_SYS;
vtime->starttime = sched_clock();
+ vtime->cpu = smp_processor_id();
write_seqcount_end(&vtime->seqcount);
}
@@ -837,6 +839,7 @@ void vtime_init_idle(struct task_struct *t, int cpu)
write_seqcount_begin(&vtime->seqcount);
vtime->state = VTIME_SYS;
vtime->starttime = sched_clock();
+ vtime->cpu = cpu;
write_seqcount_end(&vtime->seqcount);
local_irq_restore(flags);
}
--
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 ` Frederic Weisbecker [this message]
2019-10-29 9:52 ` [tip: sched/core] sched/vtime: Record CPU under seqcount for kcpustat needs 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 ` [PATCH 03/14] sched/cputime: Add vtime guest " Frederic Weisbecker
2019-10-29 9:52 ` [tip: sched/core] " 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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