Re: [PATCH] [RT] avoid preemption in memory controller code

From: Tim Blechmann
Date: Mon Dec 08 2008 - 12:08:19 EST


> > the lru_lock of struct mem_group_per_zone is used to avoid preemption
> > during the __mem_cgroup_stat_add_safe function.
> > therefore, a raw_spinlock_t should be used.
>
> What is the reason that this must avoid preemption?

it guards a call to smp_processor_id() in __mem_cgroup_stat_add_safe().
see http://article.gmane.org/gmane.linux.rt.user/3690

> Is there another
> way to solve this? I rather not just add a raw spinlock if we can
> help it.

not sure, maybe one can disable preemption for that specific function?

tim

--
tim@xxxxxxxxxx
http://tim.klingt.org

Art is either a complaint or do something else
John Cage quoting Jasper Johns

Attachment: signature.asc
Description: This is a digitally signed message part