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bh=eunUM8JQ172NyXvs2GMpTXA1jV7Ng7SV2a6H7K+qqos=; b=p/gkbFuKTFo5OjOtKB7SZOwwE8OQ40gBqwNAOscKo8TEwC8dlIoPlJR7ft6kIo3/XSEEiU b+g15YoKAOk5NfLViLB3wRqHT+WN8K+3jnS7jtgMSUPmjU5SHIFUn1s1MUEv8Z4JWg05/P sUgqL8vHdKr77yyWvOjwY7pif99PXh1axr+MyCSdFYPpFc5YdlVMIRR0AhYSwTZzsxlRv6 9I5uoJhZvDyMD18/PRqCIU3HG1NOZnG34mKgyVSBIK0CtJ3irAO5YZnaUVigmIeVxM8YLn eOYK89PTIuSx84H/pt0JROjj3wx3NHGfTbR0hmiwIE4Wduo7OEFz6UrX7Nnd2g== Content-Transfer-Encoding: quoted-printable Date: Tue, 17 Mar 2026 17:19:14 +0800 To: "Christoph Hellwig" Cc: "Vlastimil Babka (SUSE)" , "Dave Chinner" , "Harry Yoo" , "Hao Li" , "guzebing" , , , , , , , , , In-Reply-To: X-Lms-Return-Path: References: <20260115021108.1913695-1-guzebing1612@gmail.com> Content-Type: text/plain; charset=UTF-8 Message-Id: Subject: Re: [PATCH v3] iomap: add allocation cache for iomap_dio From: "changfengnan" Mime-Version: 1.0 X-Stat-Signature: 1iqrdypbrwoo3hrc7xxktpdj1cyb7b64 X-Rspam-User: X-Rspamd-Queue-Id: 38B8840006 X-Rspamd-Server: rspam12 X-HE-Tag: 1773739164-161904 X-HE-Meta: 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 xfKRetkR 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > From: "Christoph Hellwig" > Date:=C2=A0 Tue, Mar 17, 2026, 17:13 > Subject:=C2=A0 Re: [PATCH v3] iomap: add allocation cache for iomap_dio > To: "changfengnan" > Cc: "Vlastimil Babka (SUSE)", "Dave Chinner", "Harry Yoo", "Hao Li",= "guzebing", , , , , , , , , > On Tue, Mar 17, 2026 at 04:33:24PM +0800, changfengnan wrote: > > > IO is not my area but getting from 1.19M to 1.20M doesn't look like i= t's > > > worth the custom code? (possibly from 1.17M to 1.20M it also wasn't). > > Yes, at least for now, there=E2=80=99s no need for a per-CPU. > > It might be better to replace kmalloc with a new cache, but my tests so= far > > haven=E2=80=99t shown any performance improvements.=C2=A0 I=E2=80=99ll = look into it further. >=C2=A0 > Does using a kmem_cache help? =C2=A0That should generally be a nice win > anyway due to keeping the objects together. For now, my test case is just run ./t/io_uring and fio, no other process, n= ot show any performance improvements, test case is simple and no other user try to kmalloc same size object, I think maybe there will be improvements in more complex case. In theory, yes. I=E2=80=99ll run some tests to verify that. >=C2=A0