adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2025-01-01 05:36:24 +00:00
Code Issues Projects Releases Packages Wiki Activity

powerpc/pseries: Fix cpu hotplug

Browse source 
Currently, pseries_cpu_die() calls msleep() while polling RTAS for
the status of the dying cpu.

However, if the cpu that is going down also happens to be the one
doing the tick then we're hosed as the tick_do_timer_cpu 'baton' is
only passed later on in tick_shutdown() when _cpu_down() does the
CPU_DEAD notification.  Therefore jiffies won't be updated anymore.

This replaces that msleep() with a cpu_relax() to make sure we're not
going to schedule at that point.

With this patch my test box survives a 100k iterations hotplug stress
test on _all_ cpus, whereas without it, it quickly dies after ~50
iterations.

Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Sebastien Dugue 2008-11-27 00:59:52 +00:00 committed by Paul Mackerras
parent fad7b9b51e
commit b906cfa397
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/powerpc/platforms/pseries/hotplug-cpu.c
View file

@ -116,7 +116,7 @@ static void pseries_cpu_die(unsigned int cpu)
cpu_status = query_cpu_stopped(pcpu);
if (cpu_status == 0 || cpu_status == -1)
break;
msleep(200);
cpu_relax();
}
if (cpu_status != 0) {
printk("Querying DEAD? cpu %i (%i) shows %i\n",