Re: [PATCH 04/11] cgroup: use kzalloc() and list_del_init()

From: Tejun Heo
Date: Wed Jun 12 2013 - 22:56:35 EST


On Wed, Jun 12, 2013 at 07:52:02PM -0700, Kent Overstreet wrote:
> On Wed, Jun 12, 2013 at 07:48:59PM -0700, Tejun Heo wrote:
> > On Wed, Jun 12, 2013 at 07:43:10PM -0700, Kent Overstreet wrote:
> > > list_del() does do poisoning - and list debugging is cheaper to enable
> > > than full slab debugging.
> >
> > Ah, right, now we have DEBUG_LIST. Completely forgot about that. I
> > don't think the cost difference matters that much as long as there are
> > enough people running with slab debugging, but, yeah, with DEBUG_LIST,
> > leaving list_del() alone would actually be better. I'll drop that
> > part.
>
> I can't remember if it was Fedora or RH (or both?) but in one of those
> they actually leave it enabled in their production kernels. Someone was
> blogging about the bugs it found...

And we poison regardless of DEBUG_LIST and looks like have been doing
that forever. I have no idea why I was thinking list_del() didn't
poison. Maybe it was something which got stuck in my brain from
before the git history or I'm just hallucinating. Anyways, yeap,
list_del() is better.

Thanks.

--
tejun
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