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charset=us-ascii Content-Disposition: inline In-Reply-To: <20240701232224.43d5243ec9f15aa3e29a7ec5@linux-foundation.org> User-Agent: NeoMutt/20170113 (1.7.2) X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 672E78001E X-Stat-Signature: ndaebxek3z45kaozkhshagpjmfx5s1je X-Rspam-User: X-HE-Tag: 1719964905-626477 X-HE-Meta: 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 2+27eWbj 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 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: List-Subscribe: List-Unsubscribe: On Mon, Jul 01, 2024 at 11:22:24PM -0700, Andrew Morton wrote: >On Tue, 2 Jul 2024 02:09:31 +0000 Wei Yang wrote: > >> The prefetchw() is introduced from an ancient patch[1]. >> >> The change log says: >> >> The basic idea is to free higher order pages instead of going >> through every single one. Also, some unnecessary atomic operations >> are done away with and replaced with non-atomic equivalents, and >> prefetching is done where it helps the most. For a more in-depth >> discusion of this patch, please see the linux-ia64 archives (topic >> is "free bootmem feedback patch"). >> >> So there are several changes improve the bootmem freeing, in which the >> most basic idea is freeing higher order pages. And as Matthew says, >> "Itanium CPUs of this era had no prefetchers." >> >> I did 10 round bootup tests before and after this change, the data >> doesn't prove prefetchw() help speeding up bootmem freeing. The sum of >> the 10 round bootmem freeing time after prefetchw() removal even 5.2% >> faster than before. > >I don't think I've ever seen prefetch make a damn bit of difference. > >> [1]: https://lore.kernel.org/linux-ia64/40F46962.4090604@sgi.com/ >> >> Signed-off-by: Wei Yang >> Suggested-by: Matthew Wilcox >> CC: David Hildenbrand >> >> --- >> The patch is based on mm-stable with David's change. > >Oh help. David makes many changes. Please identify patches with much >care. Fully quoting the email title works, as does a link. > The commit is 3dadec1babf9eee0c67c967df931d6f0cb124a04 mm: pass meminit_context to __free_pages_core() The link is, if I am correct. https://lore.kernel.org/all/20240607090939.89524-2-david@redhat.com/ BTW, how we track the mail link? Just search in lore.kernel.org? -- Wei Yang Help you, Help me