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b=h/0JUvwrqc9fADdYseINnuUR81h0pXXKxeyvG4vnTsM35njoUbwZSEWo09fw0WCpN h+tgKdMHVHw3x6r/HjuZnAC+ELyh2JJzhDRGjSJU2omixz7cX4r3bQAwy/S4ldY2le ReLMjgqoU6252ken+TyS1q/mANDObeevQS33DrY0K8bfkPEEld0y9pSweCadeKStvO M/VADi1/oYAAft8yswpZc6KQwI1ECNYcDQSiwEqqIsavRlWGJ8JwJSTQnV5WFxRX1q SbxrxW+VhZ78tPB52sv8Q2yFuw9RwG3/mrD2ddNazOX3YPbhH/f33XG9OsmxX5jCPu XDpe4tQrka7RQ== Date: Wed, 29 Jul 2026 06:40:57 +0000 From: Harry Yoo To: "Vlastimil Babka (SUSE)" Cc: Suren Baghdasaryan , Hao Li , Shakeel Butt , Alexander Potapenko , Marco Elver , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH v3 07/13] mm/slab: replace slab.stride with obj_exts_in_object Message-ID: References: <20260727-b4-objext_split-v3-0-c29ef0f1f257@kernel.org> <20260727-b4-objext_split-v3-7-c29ef0f1f257@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260727-b4-objext_split-v3-7-c29ef0f1f257@kernel.org> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B82658000B X-Rspam-User: X-Stat-Signature: hr8yj54g6m3qoergg5hns5d9raxgbrmn X-HE-Tag: 1785307261-801156 X-HE-Meta: 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 7Kkxo12F 40WjY8/jARRlq2Mj/9g2u9kry8kCqTPKZHrjyA4gqZBBF3E5v8E9Kq5/7kVDb1kfQFUFgoMZmTcJrGf2XT6On/H/z9SfSqdSgq5+2jl1UwVM0P0PE4UkvJETAqLLpxBRZ7wH5EN3iAJj7XeBXNflD5SXZrNKZbMiQzYKYnCpVpjKUefbms/Seyp1G4VEODMLVhrTNQkSPq15p+EHduzcVnG+A6G4SI4sZHM0554LixqhtKZHkbCAYHGFVow2wjNV+JZ/+nQo6NUrhA2v/ANB4a1FBzCXR0RfpfEiLtHarWdwtqQmWrmKHCoEyJ6CrYgyuCGaO83wDMGgsTAyID0mF0PDwwRHHMtkQjjzV Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jul 27, 2026 at 02:54:01PM +0200, Vlastimil Babka (SUSE) wrote: > The stride field is used to convert object index to an slabobj_ext so > both compact arrays (kmalloc() or in-slab-leftover) and spread > in-object-padding obj_ext layouts are supported. > > In practice thus the stride is always sizeof(slabobj_ext) or s->size. > > This simplifies the calculations, but with the upcoming slabobj_ext > handling changes, it will be easier to stop storing the stride and > instead just have a flag whether obj_ext is in the object padding. > obj_exts_in_object() can then rely on this flag and slab_obj_ext() > can use that to determine the stride. > > No functional change intended. Performance impact TBD, hopefully > in the noise. Performance impact is not TBD anymore? > Reviewed-by: Suren Baghdasaryan > Reviewed-by: Hao Li > Signed-off-by: Vlastimil Babka (SUSE) > --- Looks good to me, Reviewed-by: Harry Yoo (Oracle)