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Donenfeld" Cc: Dmitry Vyukov , aryabinin@virtuozzo.com, Alexander Potapenko , cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, Andrew Morton , kasan-dev@googlegroups.com, Linux-MM , LKML , Shakeel Butt Subject: Re: Possible regression in "slab, slub: skip unnecessary kasan_cache_shutdown()" Date: Tue, 19 Jun 2018 12:21:39 -0700 Message-Id: <20180619192139.31781-1-shakeelb@google.com> X-Mailer: git-send-email 2.18.0.rc1.244.gcf134e6275-goog In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 19, 2018 at 8:19 AM Jason A. Donenfeld wrote: > > On Tue, Jun 19, 2018 at 5:08 PM Shakeel Butt wrote: > > > > 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. > > Sorry, I meant to mention that earlier. I tried with SLAB; the crash > does not occur. This appears to be SLUB-specific. Jason, can you try the following patch? --- mm/slub.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/slub.c b/mm/slub.c index a3b8467c14af..746cfe4515c2 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3673,9 +3673,17 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) bool __kmem_cache_empty(struct kmem_cache *s) { + int cpu; int node; struct kmem_cache_node *n; + for_each_online_cpu(cpu) { + struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); + + if (c->page || slub_percpu_partial(c)) + return false; + } + for_each_kmem_cache_node(s, node, n) if (n->nr_partial || slabs_node(s, node)) return false; -- 2.18.0.rc1.244.gcf134e6275-goog