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Tue, 20 Oct 2026 02:32:54 +0000 X-Mizu-Trace-ID: 8af93f4628e3430e X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Archived-By: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH v3] mm/shrinker: allocate shrinker_info_unit from a dedicated kmem_cache From: Muchun Song In-Reply-To: <20261019-vstor-144715-shrinker_info_unit-kmem_cache-v3-1-0fb061e09bf4@virtuozzo.com> Date: Tue, 20 Oct 2026 10:32:34 +0800 Cc: Andrew Morton , Dave Chinner , Qi Zheng , Roman Gushchin , Johannes Weiner , Michal Hocko , Shakeel Butt , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <285B262E-95AF-4BBD-923C-922DDDF0E70C@linux.dev> References: <20261019-vstor-144715-shrinker_info_unit-kmem_cache-v3-1-0fb061e09bf4@virtuozzo.com> To: Konstantin Khorenko X-Mailer: Apple Mail (2.3901.100.1.1.12) X-Rspamd-Queue-Id: F23B8120006 X-Rspam-User: X-Stat-Signature: 7b7ou7qxj6e4g3cxkw4ew8fjcxjgz1ab X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam03 X-HE-Tag: 1792463575-828329 X-HE-Meta: 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 w7nAuYAX D4JIZZU0kaWSrSnI6Y8GHP3BQS0FLEAGshLeR4xLgv8cnWPFHoNpWmxs5GcDwGLZYFYvcCMG0iHypedtpQGfOTqv14Y35iMShLALmtmvUWH8jG57SxFRkcmz7hCK05hwSmTLq8TQCRPghWGFlUmW26y0mAFurR/VF44jkPyDem+NzvuR4JKpEJL1H+gVU4Qh+naYXQ81pU/oV+5np4iVnHC5VcxKa6cfPd2/omHt2dvI/YCItZWjMKjj8JJqNblpzDRFRbBcPJwePEhpps5Z+HybD+KAyF5My1WmvPWQhOTGhEkOrjDs1E4tERaHJrWM74cb6TTMMpu2rRjILTfzJH6r/QD+NAygN+GMU32vlczonKRziOcJM+IxhQ+Xa9uApJnZ7lsVDL5iWPVMSGq7kG64gx0optvsTXURkQLwEVwyc3hzh7lWNyMLA7w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 > On Oct 20, 2026, at 00:11, Konstantin Khorenko = wrote: >=20 > shrinker_info_unit holds BITS_PER_LONG atomic_long_t of deferred work > plus a one-word bitmap, 520 bytes on 64-bit. kzalloc_node() takes it > from kmalloc-1k, so almost half of every unit is padding. >=20 > Allocate the units from a cache of their own, sized to the unit. The > cache is not cache-line aligned: the counters of a unit already share > cache lines between shrinkers, and aligning the unit would only keep > neighbouring units off each other's boundary line, at the cost of part > of the saving. >=20 > Suggested-by: Andrew Morton > Assisted-by: LLM > Signed-off-by: Konstantin Khorenko Acked-by: Muchun Song Thanks.