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From: Muchun Song In-Reply-To: <20251218150949.721480-14-kas@kernel.org> Date: Mon, 22 Dec 2025 14:30:56 +0800 Cc: Andrew Morton , David Hildenbrand , Matthew Wilcox , Usama Arif , Frank van der Linden , Oscar Salvador , Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Zi Yan , Baoquan He , Michal Hocko , Johannes Weiner , Jonathan Corbet , kernel-team@meta.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <324C52CD-0E8C-412F-BA33-0F605C1B7AC3@linux.dev> References: <20251218150949.721480-1-kas@kernel.org> <20251218150949.721480-14-kas@kernel.org> To: Kiryl Shutsemau X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: BFE83120012 X-Stat-Signature: kfph6ctx9i3mr1cedjo5gjurcibhd5gh X-Rspam-User: X-HE-Tag: 1766385127-948492 X-HE-Meta: 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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 Dec 18, 2025, at 23:09, Kiryl Shutsemau wrote: > > The compound_head() function is a hot path. For example, the zap path > calls it for every leaf page table entry. > > Rewrite the helper function in a branchless manner to eliminate the risk > of CPU branch misprediction. > > Signed-off-by: Kiryl Shutsemau Reviewed-by: Muchun Song Thanks.