Le Mon, Jun 10, 2024 at 06:26:21PM -0000, tip-bot2 for Oleg Nesterov a écrit :
The following commit has been merged into the timers/urgent branch of tip:
Commit-ID: 07c54cc5988f19c9642fd463c2dbdac7fc52f777 Gitweb: https://git.kernel.org/tip/07c54cc5988f19c9642fd463c2dbdac7fc52f777 Author: Oleg Nesterov oleg@redhat.com AuthorDate: Tue, 28 May 2024 14:20:19 +02:00 Committer: Thomas Gleixner tglx@linutronix.de CommitterDate: Mon, 10 Jun 2024 20:18:13 +02:00
tick/nohz_full: Don't abuse smp_call_function_single() in tick_setup_device()
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
I think we agreed on that version actually:
https://lore.kernel.org/all/20240603153557.GA8311@redhat.com/
Thanks.