alpha: Send stop IPI to send to online CPUs

This issue was noticed while debugging a shutdown issue where some
secondary CPUs are not being shutdown correctly.  A fix for that [1] requires
that secondary cpus be offlined using the cpu_online_mask so that the
stop operation is a no-op if CPU HOTPLUG is disabled.  I, like the author in
[1] looked at the architectures and found that alpha is one of two
architectures that executes smp_send_stop() on all possible CPUs.

On alpha, smp_send_stop() sends an IPI to all possible CPUs but only needs
to send them to online CPUs.

Send the stop IPI to only the online CPUs.

[1] https://lkml.org/lkml/2020/1/10/250

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Matt Turner <mattst88@gmail.com>
This commit is contained in:
Prarit Bhargava 2021-01-05 10:16:27 -05:00 committed by Matt Turner
parent f0443da1d8
commit caace6ca4e
1 changed files with 1 additions and 1 deletions

View File

@ -582,7 +582,7 @@ void
smp_send_stop(void)
{
cpumask_t to_whom;
cpumask_copy(&to_whom, cpu_possible_mask);
cpumask_copy(&to_whom, cpu_online_mask);
cpumask_clear_cpu(smp_processor_id(), &to_whom);
#ifdef DEBUG_IPI_MSG
if (hard_smp_processor_id() != boot_cpu_id)