On Mon, Jun 17, 2024 at 10:35:10PM +0200, Thomas Gleixner wrote:
>
> From: Oleg Nesterov <oleg@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Link: https://lore.kernel.org/r/20240528122019.GA28794@xxxxxxxxxx
> Link: https://lore.kernel.org/all/20240522151742.GA10400@xxxxxxxxxx
> ---
> Backport to v6.6.y and earlier
Now queued up, thanks.
greg k-h
