Re: [PATCH] memcg: fix memcg_cache_name() to use cgroup_name()

From: Michal Hocko
Date: Fri Mar 22 2013 - 05:31:54 EST


On Fri 22-03-13 12:22:23, Glauber Costa wrote:
> On 03/22/2013 12:17 PM, Li Zefan wrote:
> >> GFP_TEMPORARY groups short lived allocations but the mem cache is not
> >> > an ideal candidate of this type of allocations..
> >> >
> > I'm not sure I'm following you...
> >
> > char *memcg_cache_name()
> > {
> > char *name = alloc();
> > return name;
> > }
> >
> > kmem_cache_dup()
> > {
> > name = memcg_cache_name();
> > kmem_cache_create_memcg(name);
> > free(name);
> > }
> >
> > Isn't this a short lived allocation?
> >
>
> Hi,
>
> Thanks for identifying and fixing this.
>
> Li is right. The cache name will live long, but this is because the
> slab/slub caches will strdup it internally. So the actual memcg
> allocation is short lived.

OK, I have totally missed that. Sorry about the confusion. Then all the
churn around the allocation is pointless, no?
What about:
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