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Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vS94v-00000008990-3uRg; Sun, 07 Dec 2025 07:21:10 +0000 Date: Sun, 7 Dec 2025 07:21:09 +0000 From: Matthew Wilcox To: Mateusz Guzik Cc: oleg@redhat.com, brauner@kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Subject: Re: [PATCH v3 2/2] pid: only take pidmap_lock once on alloc Message-ID: References: <20251206131955.780557-1-mjguzik@gmail.com> <20251206131955.780557-3-mjguzik@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251206131955.780557-3-mjguzik@gmail.com> X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: A943E100008 X-Stat-Signature: yw3gtbwm3fwo6s5a359bi7ceychx8h3n X-Rspam-User: X-HE-Tag: 1765092073-19437 X-HE-Meta: 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 QQPlf+/d EfA0mz/g5nwyIndvnvCU/+UyMLFc+oXj7jcCbkIbfhW7w0NeBjgQxRexjeyn38tinp08Y8UIPp8OtNhy4KfTRrZakzGt3Gl9m2O8XDz6+0I85QrW7Xdn3jvTmKj1HNUnyrZCO2tbPMIeqU+JSJ/mv1Wfk48Z9MZEUJGE9zuuCSYOS9FtCw+/WtY5DpGigyjxby2gWHaPWMKRD1mKMvC34D2LLa4qNYPlKDylt0oDiS8X6Jyd56lS15gEhOsj9fDu3Si9iCuMHP/1m8UOdcaJTkwkqMRE9x/Wq2QwWTvoMjY1febw= 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 Sat, Dec 06, 2025 at 02:19:55PM +0100, Mateusz Guzik wrote: > - if (!pid) > + if (unlikely(!pid)) Does this change anything? I was under the impression that gcc already treats !p as unlikely.