brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

timer: Fix hotplug regression 

The recent timer wheel rework removed the get/put_cpu_var() pair in
the hotplug migration code, which results in:

BUG: using smp_processor_id() in preemptible [00000000] code: hib.sh/2845
...
[<ffffffff810d4fa3>] timer_cpu_notify+0x53/0x12

That hunk is a leftover from an earlier iteration and went unnoticed
so far.

Restore the previous code which was obviously correct.

Fixes: 0eeda71bc3 'timer: Replace timer base by a cpu index'
Reported-and_tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2015-06-26 22:08:38 +02:00
parent 56a94f1391
commit 24bfcb1009
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
kernel/time/timer.c
View File

@ -1566,7 +1566,7 @@ static void migrate_timers(int cpu)
BUG_ON(cpu_online(cpu));
old_base = per_cpu_ptr(&tvec_bases, cpu);
new_base = this_cpu_ptr(&tvec_bases);
new_base = get_cpu_ptr(&tvec_bases);
/*
* The caller is globally serialized and nobody else
* takes two locks at once, deadlock is not possible.
@ -1590,6 +1590,7 @@ static void migrate_timers(int cpu)
spin_unlock(&old_base->lock);
spin_unlock_irq(&new_base->lock);
put_cpu_ptr(&tvec_bases);
}
static int timer_cpu_notify(struct notifier_block *self,