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b=SETtaNlQ7OqsZkRg+4F2KmbHGav+xCxS/suET8Op3SQDNp6N3sLYa3YJsMTWYO6f/ hMDLtHhnUNRMTE0I5Khqn8cm6ednL+pf58FJ85kw4j8BIcStIJNHpVhDAMPSxWuHi/ fxPM6wqJo7EZlC3gdIdLI3DoJQzr6cU5PlGTprW9KJuRE5+ui1Mz9fJya2BoyJG6CY J6+JjLmTxOr361wRJFO8z19ZKI72DQm7lA57p5HhXFjpHiDWPXuezeD3J5ZfKaCFu2 hpQqeGuoZv96PdCasfN/hK0iibtlzBPkCbzVpSUVzQ/M9rS9pbbJJuf9FS9jHtblBH 640xeM4gu4FTw== Date: Thu, 5 Nov 2026 13:12:23 +0000 From: Harry Yoo To: "Vlastimil Babka (SUSE)" Cc: Andrey Ryabinin , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Geert Uytterhoeven , Conor Dooley , Damien Le Moal , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , kasan-dev@googlegroups.com Subject: Re: [PATCH v3 03/10] mm, slab: refactor slab_min/max_order handling Message-ID: References: <20261105-slub_tiny_rework-v3-0-0484ce59eabb@kernel.org> <20261105-slub_tiny_rework-v3-3-0484ce59eabb@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261105-slub_tiny_rework-v3-3-0484ce59eabb@kernel.org> X-Stat-Signature: b8resuj6put6h63yoaua5h4mynjij5z3 X-Rspamd-Server: rspam01 X-Rspam-User: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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-Queue-Id: 7B6814000A X-HE-Tag: 1793884346-899113 X-HE-Meta: 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 lwvSbz+K fqt/M7ScTrGf6C4G36RBEEaHmO09XnZwWRHmarhm0fdyRsIv3xF2JHlWYNwZeCW7SFgCXDVvQq3CrB78cWVo55au4CymigRaTJh51mDUEwL8IVZM8LFi7HvTzt+bvnmSh9lMMB6nsC7m6uhmUtlEyqlefprD7Fwy2T4r6m0zLFdj3z/oqV1p461QhZJSmvBwszCVeugJ6wClEzOzuJLFXLW+BFmfaq9SZEZZeyd+aZcgxs3RqFHIsoIE4hZMqUj3Yl4YJt7RLUH/0wYZ8vArVyqtQ7aNfFDa4B0RfnKzTmPaRJT4QGlmlhDOapS7TJ3wIr06/hJfK7Hj4hExqmWhHQNyklob9/RTLGyesSVG+r1nCbskjsv2uSEOPqoelyTjoPoL+CkNs1o46xVk= 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 Thu, Nov 05, 2026 at 09:43:52AM +0100, Vlastimil Babka (SUSE) wrote: > Setting slab_min_order and slab_max_order as boot-time parameters > currently has several not so great aspects: > > - slab_min_order is not checked against MAX_PAGE_ORDER > - slab_min_order can raise slab_max_order > - processing requires custom callbacks, their execution order > depends on the order of boot time parameters specified > - upcoming SLUB_TINY changes would be more complicated > > Instead of custom callbacks, introduce __initdata variables that hold > the boot-time parameter values (if given). All inputs are then evaluated > deterministically in kmem_cache_init(). slab_min_order is always capped > at slab_max_order and cannot raise it. > > debug_guardpage_minorder() still overrides any given boot time params, > but it could be changed if there's a use case. > > While at it, rename the slub_min/max_order variables and > slub_min_objects to have a "slab_" prefix instead, as their values > determine the sizing of slabs, and the "slub_" prefix already became > deprecated also for the boot-time parameters. > > Signed-off-by: Vlastimil Babka (SUSE) > --- Looks good to me, Reviewed-by: Harry Yoo (Meta) -- Cheers, Harry / Hyeonggon