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Sun, 14 Aug 2022 17:04:17 -0700 (PDT) Date: Sun, 14 Aug 2022 17:04:16 -0700 (PDT) From: David Rientjes To: Vlastimil Babka cc: Rongwei Wang , Christoph Lameter , Joonsoo Kim , Pekka Enberg , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin , linux-mm@kvack.org, Sebastian Andrzej Siewior , Thomas Gleixner , Mike Galbraith Subject: Re: [PATCH 3/5] mm/slub: remove slab_lock() usage for debug operations In-Reply-To: <20220812091426.18418-4-vbabka@suse.cz> Message-ID: References: <20220812091426.18418-1-vbabka@suse.cz> <20220812091426.18418-4-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660521859; a=rsa-sha256; cv=none; b=M610xpExePf4YOTn2oXqafRfOcCDvGKIPZbjvIau3FjfePEmgr+oC3yFOho8C2zVmoA2l3 ymOHgRZdQI66dGSSk77JOsk71lqdEjNZFnjYJRgwWy6qcO9useX1TV+KiBKryU8Yt14ws6 y9DemrFX8AyLBxUeqYcsfvly9dI38wA= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Dnqeds1Y; 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dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1660521859-547654 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 12 Aug 2022, Vlastimil Babka wrote: > All alloc and free operations on debug caches are now serialized by > n->list_lock, so we can remove slab_lock() usage in validate_slab() > and list_slab_objects() as those also happen under n->list_lock. > > Note the usage in list_slab_objects() could happen even on non-debug > caches, but only during cache shutdown time so there should not be any > parallel freeing activity anymore. Except for buggy slab users, but in > that case the slab_lock() would not help against the common cmpxchg > based fast paths (in non-debug caches) anyway. > > Also adjust documentation comments accordingly. > > Suggested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > Signed-off-by: Vlastimil Babka Acked-by: David Rientjes