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Sun, 09 Jul 2023 07:42:19 -0700 (PDT) MIME-Version: 1.0 References: <20230628095740.589893-1-jaypatel@linux.ibm.com> In-Reply-To: From: Hyeonggon Yoo <42.hyeyoo@gmail.com> Date: Sun, 9 Jul 2023 23:42:08 +0900 Message-ID: Subject: Re: [PATCH] [RFC PATCH v2]mm/slub: Optimize slub memory usage To: David Rientjes Cc: Jay Patel , =?UTF-8?B?QnJpYW4g4oCcQmluZGVy4oCdIE1ha2lu?= , linux-mm@kvack.org, cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com, Andrew Morton , Vlastimil Babka , aneesh.kumar@linux.ibm.com, tsahu@linux.ibm.com, piyushs@linux.ibm.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: B24A540011 X-Rspam-User: X-Stat-Signature: tj8n6w49eh6o9tbqrspeuw6xxe5yuc19 X-Rspamd-Server: rspam03 X-HE-Tag: 1688913740-664482 X-HE-Meta: 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 UVaqRNdH 9HCgM99zz427hDEKg2FMBZjVcB9UlApS20O4nt7sWGTH5QsvgCC+WTmIwsE/7IryABwLYURGFsRDYWkxYL/zsVXzfc6GIRMIPM7MzjmGjH5d8U3k5EgsimzZ9dgixf9sYupaGs6/BAhFoBpQkLjb7QHb8pL43BvLedpVPsQNcq3RhTkohBQti1YSgTprDc2++LQ1BXJQKc9mehdlbHXGNrzd7EpvS7DhVHUY3oCbNhYH52PpxaNk3qBdi2wBSFEG5ZLspSIXwhXS88teAVkHkp0OiqXj8NurCj0ehg5L8KDIa/3BNuqUowQIQt8VWoDJ0eXz9WdmbG4whCbzGWw6g5XQTOtsO6SaATGtWKd3SyqP6GZdICUEBRmjjv950WtSOvR1fjFwu5C7VWPGIT4jUG6Gimg== 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 Mon, Jul 3, 2023 at 9:13=E2=80=AFAM David Rientjes = wrote: > > Thanks very much for looking at this, Jay! > > My colleague, Binder, has also been looking at opportunities to optimize > memory usage when using SLUB. We're preparing to deprecate SLAB > internally and shift toward SLUB since SLAB is scheduled for removal afte= r > the next LTS kernel. > > Binder, do you have an evaluation with this patch similar to what Jay did= ? > > Also, tangentially: we are looking at other opportunities for reduction i= n > memory overhead when using SLUB. If you or anybody else are interested i= n > being involved in a working group with this shared goal, please let me > know. We could brainstorm, collaborate, and share data. I'm also interested in reducing SLUB memory overhead! I have some rough ideas, which should be evaluated further: 1. Lengthen or shrink number of cached objects per CPU based on list_lock contention. 2. Modify SLUB to enable linking objects from different slabs into the CPU freelist. Do you have any opinions, or are there any approaches you are already exami= ning? -- Hyeonggon