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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 19 Jun 2018 08:08:27 -0700
Message-ID: <CALvZod7MfTTwbfG3zC1kGrZB1Cf0UAnbvdbqhC5Dm=uy6=DtOg@mail.gmail.com>
Subject: Re: Possible regression in "slab, slub: skip unnecessary kasan_cache_shutdown()"
To:     Jason@zx2c4.com
Cc:     Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        kasan-dev@googlegroups.com, Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Jun 19, 2018 at 6:05 AM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
>
> HI Dimitry,
>
> On Tue, Jun 19, 2018 at 6:55 AM Dmitry Vyukov <dvyukov@google.com> wrote:
> > Your code frees all entries before freeing the cache, right? If you
> > add total_entries check before freeing the cache, it does not fire,
> > right?
>
> Yes, certainly.
>
> > Are you using SLAB or SLUB? We stress kernel pretty heavily, but with
> > SLAB, and I suspect Shakeel may also be using SLAB. So if you are
> > using SLUB, there is significant chance that it's a bug in the SLUB
> > part of the change.
>
> Nice intuition; I am indeed using SLUB rather than SLAB...
>

Can you try once with SLAB? Just to make sure that it is SLUB specific.