From: Frederic Weisbecker <frederic@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Yunfeng Ye <yeyunfeng@huawei.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Frederic Weisbecker <frederic@kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>
Subject: [PATCH 4/8] tick/nohz: Update idle_exittime on actual idle exit
Date: Thu, 22 Apr 2021 14:01:54 +0200 [thread overview]
Message-ID: <20210422120158.33629-5-frederic@kernel.org> (raw)
In-Reply-To: <20210422120158.33629-1-frederic@kernel.org>
From: Yunfeng Ye <yeyunfeng@huawei.com>
The idle_exittime field of tick_sched is used to record the time when
the idle state was left. but currently the idle_exittime is updated in
the function tick_nohz_restart_sched_tick(), which is not always in idle
state when nohz_full is configured:
tick_irq_exit
tick_nohz_irq_exit
tick_nohz_full_update_tick
tick_nohz_restart_sched_tick
ts->idle_exittime = now;
It's thus overwritten by mistake on nohz_full tick restart. Move the
update to the appropriate idle exit path instead.
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Cc: Yunfeng Ye <yeyunfeng@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
kernel/time/tick-sched.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 31efd55ed302..ffc13b9dfbe3 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -921,8 +921,6 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
- ts->idle_exittime = now;
-
tick_nohz_restart(ts, now);
}
@@ -1190,10 +1188,13 @@ unsigned long tick_nohz_get_idle_calls(void)
return ts->idle_calls;
}
-static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
+static void tick_nohz_account_idle_time(struct tick_sched *ts,
+ ktime_t now)
{
unsigned long ticks;
+ ts->idle_exittime = now;
+
if (vtime_accounting_enabled_this_cpu())
return;
/*
@@ -1214,8 +1215,9 @@ void tick_nohz_idle_restart_tick(void)
struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
if (ts->tick_stopped) {
- tick_nohz_restart_sched_tick(ts, ktime_get());
- tick_nohz_account_idle_ticks(ts);
+ ktime_t now = ktime_get();
+ tick_nohz_restart_sched_tick(ts, now);
+ tick_nohz_account_idle_time(ts, now);
}
}
@@ -1226,7 +1228,7 @@ static void tick_nohz_idle_update_tick(struct tick_sched *ts, ktime_t now)
else
tick_nohz_restart_sched_tick(ts, now);
- tick_nohz_account_idle_ticks(ts);
+ tick_nohz_account_idle_time(ts, now);
}
/**
--
2.25.1
next prev parent reply other threads:[~2021-04-22 12:02 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 12:01 [PATCH 0/8] tick/nohz updates v2 Frederic Weisbecker
2021-04-22 12:01 ` [PATCH 1/8] tick/nohz: Evaluate the CPU expression after the static key Frederic Weisbecker
2021-05-04 12:31 ` Peter Zijlstra
2021-04-22 12:01 ` [PATCH 2/8] tick/nohz: Conditionally restart tick on idle exit Frederic Weisbecker
2021-04-22 12:01 ` [PATCH 3/8] tick/nohz: Remove superflous check for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE Frederic Weisbecker
2021-05-04 12:40 ` Peter Zijlstra
2021-04-22 12:01 ` Frederic Weisbecker [this message]
2021-04-22 12:01 ` [PATCH 5/8] tick/nohz: Update nohz_full Kconfig help Frederic Weisbecker
2021-04-22 12:01 ` [PATCH 6/8] tick/nohz: Only wakeup a single target cpu when kicking a task Frederic Weisbecker
2021-05-05 13:43 ` Peter Zijlstra
2021-05-10 10:39 ` Frederic Weisbecker
2021-05-10 10:48 ` Peter Zijlstra
2021-05-10 10:54 ` Frederic Weisbecker
2021-04-22 12:01 ` [PATCH 7/8] tick/nohz: Change signal tick dependency to wakeup CPUs of member tasks Frederic Weisbecker
2021-04-22 12:01 ` [PATCH 8/8] tick/nohz: Kick only _queued_ task whose tick dependency is updated Frederic Weisbecker
2021-05-05 13:57 ` Peter Zijlstra
2021-05-10 10:52 ` Frederic Weisbecker
2021-05-05 13:57 ` [PATCH 0/8] tick/nohz updates v2 Peter Zijlstra
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