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Howlett" , ebiederm@xmission.com, oleg@redhat.com, brauner@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/6] exit: hoist get_pid() in release_task() outside of tasklist_lock Message-Id: <20250203175128.80319b42c9739f0d420080a4@linux-foundation.org> In-Reply-To: References: <20250201163106.28912-1-mjguzik@gmail.com> <20250201163106.28912-3-mjguzik@gmail.com> <2f3gjvg6zwp2xpkhb2e36ux2resnjdtxuinbbgnr57jdqesrm6@oau2dgx63fxy> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9C1A31C0009 X-Stat-Signature: 9h6j663375q4n1zz33ui6bfuzry5qhu4 X-Rspam-User: X-HE-Tag: 1738633890-175669 X-HE-Meta: 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 LMBRGpNj 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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, 3 Feb 2025 21:22:31 +0100 Mateusz Guzik wrote: > On Mon, Feb 3, 2025 at 9:14 PM Liam R. Howlett wrote: > > > > * Mateusz Guzik [250203 14:36]: > > > On Mon, Feb 3, 2025 at 8:27 PM Liam R. Howlett wrote: > > > > > > > > * Mateusz Guzik [250201 11:31]: > > > > > Signed-off-by: Mateusz Guzik > > > > > > > > Change log is a bit sparse? I get that the subject spells out what is > > > > done, but anything to say here at all? Reduces lock contention by > > > > reducing lock time or something? Maybe even some numbers you have in > > > > the cover letter? > > > > > > > > > > I did not measure this bit *specifically*. > > > > > > As one can expect get_pid issues an atomic and that's slow. And since > > > it can happen *prior* to taking the global lock it seems like an > > > obvious little nit to sort out. > > > > > > I would argue the change is self-explanatory given the cover-letter. > > > > But when you git blame on the file, you will not see that cover letter. > > if this lands, I presume it is going to go through Andrew who uses > tooling pulling in the cover letter for each commit No, I copy the [0/n] description into the [1/n] changelog only. > but i'm not going to argue this bit, just provide with a commit > message which you think works and I'll use it It's rather irregular to ask Liam to explain your patch! The Subject: describes what the patch does (which was obvious from the code anyway) but the changelog fails to explain *why* the change was made. You've explained "why" adequately within this discussion so I suggest you condense those words into this patch's changelog. General muse: if a reviewer asks questions regarding a patch then we should treat those questions as bug reports against the changelogs and code comments: required information is missing. So please let's go through reviewer questions as we prepare the next revision of a patchset and make sure that all those questions are fully answered,