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]
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