Re: [REGRESSION] [PATCH 1/3] mm/slab: use percpu allocator for cpu cache

From: Joonsoo Kim
Date: Mon Sep 29 2014 - 03:44:28 EST


On Sat, Sep 27, 2014 at 11:24:49PM -0700, Jeremiah Mahler wrote:
> On Thu, Aug 21, 2014 at 05:11:13PM +0900, Joonsoo Kim wrote:
> > Because of chicken and egg problem, initializaion of SLAB is really
> > complicated. We need to allocate cpu cache through SLAB to make
> > the kmem_cache works, but, before initialization of kmem_cache,
> > allocation through SLAB is impossible.
> >
> > On the other hand, SLUB does initialization with more simple way. It
> > uses percpu allocator to allocate cpu cache so there is no chicken and
> > egg problem.
> >
> > So, this patch try to use percpu allocator in SLAB. This simplify
> > initialization step in SLAB so that we could maintain SLAB code more
> > easily.
> >
> > From my testing, there is no performance difference.
> >
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
>
> I just encountered a problem on a Lenovo Carbon X1 where it will
> suspend but won't resume. A bisect indicated that this patch
> is causing the problem.
>
> 997888488ef92da365b870247de773255227ce1f
>
> I imagine the patch author, Joonsoo Kim, might have a better idea
> why this is happening than I do. But if I can provide any information
> or run any tests that might be of help just let me know.

Hello,

Yeah, there is a bug. Below will fix your issue.
Could you test it and report the result?

Thanks for reporting it.

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