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charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20230418191313.268131-4-hannes@cmpxchg.org> X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: A49E08001A X-Stat-Signature: kwn7qnq8hq8j3cn5h4ohjbzn5znfozz1 X-HE-Tag: 1682080642-822470 X-HE-Meta: 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 Qer6i83f fbWQKC8PEYO01EH2W5hg/7l6t9ijS/cAwhZFjbyd69C7LwPy2qWpylzqEdObrYtOjVbo1uBOWv0/8NuER1aBZDNfVIXj3XktutcGXXThqy5vMIakbuTBwTPast4nKQJmm76Fb0CZkNy6+hN8GdHHIuZdjNBrWOTWBfw156rt+Q11IPFSQSE60kAsxiWquLqywi6AqBOdE0WiiyrUsY6UsXDbjMX7tgWJxvk4y+7HrgDtxtdPyfKwmMh+XRp3/gibEkV3P2pTizP3Gf/3XdptyFPbvFw== 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 Tue, Apr 18, 2023 at 03:12:50PM -0400, Johannes Weiner wrote: > pageblock_order can be of various sizes, depending on configuration, > but the default is MAX_ORDER-1. Given 4k pages, that comes out to > 4M. This is a large chunk for the allocator/reclaim/compaction to try > to keep grouped per migratetype. It's also unnecessary as the majority > of higher order allocations - THP and slab - are smaller than that. > > Before subsequent patches increase the effort that goes into > maintaining migratetype isolation, it's important to first set the > defrag block size to what's likely to have common consumers. > > Signed-off-by: Johannes Weiner This patch may be a distraction in the context of this series. I don't feel particularly strongly about it but it has strong bikeshed potential. For configurations that support huge pages of any sort, it should be PMD_ORDER, for anything else the choice is arbitrary. 2M is as good a guess as anyway because even if it was tied to the PAGE_ALLOC_COSTLY_ORDER then the pageblock bitmap overhead might be annoying. -- Mel Gorman SUSE Labs