From: Frederic Weisbecker <frederic@kernel.org>
To: He Zhe <zhe.he@windriver.com>
Cc: anna-maria@linutronix.de, linux-kernel@vger.kernel.org,
tglx@linutronix.de
Subject: Re: [PATCH v2] timers: Recalculate next timer interrupt only when necessary
Date: Thu, 8 Jul 2021 17:36:20 +0200 [thread overview]
Message-ID: <20210708153620.GA6716@lothringen> (raw)
In-Reply-To: <dfbf752e-91db-b128-76a8-98fde4c5d480@windriver.com>
On Thu, Jul 08, 2021 at 02:43:01PM +0800, He Zhe wrote:
> Hi,
>
> Ever since this commit merged in, when nohz_full enabled, the counts of arch_timer interrupt on arm64 arches keep increasing on cores that have been isolated. This can be reproduced on several arm64 boards. After reverting the commit, the counts would stop increasing after boot. my .config is attached.
>
> root@qemuarm64:~# uname -a
> Linux qemuarm64 5.13.0 #1 SMP PREEMPT Mon Jul 5 07:11:27 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux
> root@qemuarm64:~# cat /proc/cmdline
> root=/dev/vda rw mem=2048M ip=dhcp console=ttyAMA0 console=hvc0 earlyprintk isolcpus=1-5 nohz_full=1-5 rcu_nocbs=1-5
> root@qemuarm64:~# cat /proc/interrupts
And I'm not observing that on default aarch64 on qemu either.
Are you emulating a specific machine?
Can you enable the following trace events and send me the output from
one of the isolated CPU trace, say CPU 3 for example:
DIR=/sys/kernel/debug/tracing
echo 1 > $DIR/events/irq/enable
echo 1 > $DIR/events/sched/sched_switch/enable
echo 1 > $DIR/events/irq_vectors/enable
echo 1 > $DIR/events/workqueue/workqueue_execute_start/enable
echo 1 > $DIR/events/timer/hrtimer_expire_entry/enable
echo 1 > $DIR/events/timer/timer_expire_entry/enable
echo 1 > $DIR/events/timer/tick_stop/enable
sleep 10
cat $DIR/per_cpu/cpu0/trace > ~/output_to_send
next prev parent reply other threads:[~2021-07-08 15:36 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 15:16 [PATCH v2] timers: Recalculate next timer interrupt only when necessary Frederic Weisbecker
2020-07-24 10:59 ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2021-07-08 6:43 ` [PATCH v2] " He Zhe
2021-07-08 11:35 ` Frederic Weisbecker
2021-07-08 15:36 ` Frederic Weisbecker [this message]
2021-07-09 5:37 ` He Zhe
2021-07-09 8:43 ` Frederic Weisbecker
2021-07-09 9:25 ` He Zhe
2021-07-09 14:06 ` Nicolas Saenz Julienne
2021-07-09 14:13 ` [PATCH] timers: Fix get_next_timer_interrupt() with no timers pending Nicolas Saenz Julienne
2021-07-10 0:52 ` Frederic Weisbecker
2021-07-12 10:19 ` Nicolas Saenz Julienne
2021-07-16 16:38 ` Nicolas Saenz Julienne
2021-07-19 13:54 ` Frederic Weisbecker
2021-07-10 9:05 ` Frederic Weisbecker
2021-07-12 6:04 ` He Zhe
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