From: Greg KH <gregkh@linuxfoundation.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: oleg@redhat.com, stable@vger.kernel.org
Subject: Re: [PATCH 6.6.y and earlier] tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device()
Date: Wed, 19 Jun 2024 11:28:25 +0200 [thread overview]
Message-ID: <2024061917-sheet-galvanize-56e6@gregkh> (raw)
In-Reply-To: <87ed8vs3y9.ffs@tglx>
On Mon, Jun 17, 2024 at 10:35:10PM +0200, Thomas Gleixner wrote:
>
> From: Oleg Nesterov <oleg@redhat.com>
>
> commit 07c54cc5988f19c9642fd463c2dbdac7fc52f777 upstream.
>
> After the recent commit 5097cbcb38e6 ("sched/isolation: Prevent boot crash
> when the boot CPU is nohz_full") the kernel no longer crashes, but there is
> another problem.
>
> In this case tick_setup_device() calls tick_take_do_timer_from_boot() to
> update tick_do_timer_cpu and this triggers the WARN_ON_ONCE(irqs_disabled)
> in smp_call_function_single().
>
> Kill tick_take_do_timer_from_boot() and just use WRITE_ONCE(), the new
> comment explains why this is safe (thanks Thomas!).
>
> Fixes: 08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full")
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: stable@vger.kernel.org
> Link: https://lore.kernel.org/r/20240528122019.GA28794@redhat.com
> Link: https://lore.kernel.org/all/20240522151742.GA10400@redhat.com
> ---
> Backport to v6.6.y and earlier
Now queued up, thanks.
greg k-h
prev parent reply other threads:[~2024-06-19 9:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-17 17:54 FAILED: patch "[PATCH] tick/nohz_full: Don't abuse smp_call_function_single() in" failed to apply to 6.6-stable tree gregkh
2024-06-17 20:35 ` [PATCH 6.6.y and earlier] tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device() Thomas Gleixner
2024-06-19 9:28 ` Greg KH [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2024061917-sheet-galvanize-56e6@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=oleg@redhat.com \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.