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b=lZ8ZnK/Y14ogo/bQCAeGfOtg3ocivHsmkLuiUhPVCqMIarhhSFoMpeINgMrMFyNZB r7g2c7ISOz2x/JUikftn8t2e8vw7ceqpL6UnCWbvRqAnxKf2S0SGjhNmAOFZ3wi3yZ WzcGinpVqsoCQ6Ldq7MwMOSQ7R8iLn8Vqdi27H/E= Date: Sun, 26 Apr 2026 12:59:41 -0700 From: Andrew Morton To: Suren Baghdasaryan Cc: liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, david@redhat.com, willy@infradead.org, jannh@google.com, paulmck@kernel.org, pfalcato@suse.de, shuah@kernel.org, hsukrut3@gmail.com, richard.weiyang@gmail.com, reddybalavignesh9979@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v2 0/3] use vma locks for proc/pid/{smaps|numa_maps} reads Message-Id: <20260426125941.9921d585e2c5033e68ddb9a1@linux-foundation.org> In-Reply-To: <20260426062718.1238437-1-surenb@google.com> References: <20260426062718.1238437-1-surenb@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 5kknzygop3wdgoye5cxaax345j8suerx X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 1279FC0007 X-Rspam-User: X-HE-Tag: 1777233583-806462 X-HE-Meta: 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 Tbb7Dkpo zRs+SlK81qpcoiacze6s+PorqS1gpbkMTogRQw13OZH8hS9Mbq1nRsvSc4m7ABrykeJDU0xfqAU+B8ClcZxcZAwbrsARwGDOhpIDL11wfF9Y3P98aWKHN60UBGKLJgmNxmMeNlJnNYNN0cD3FKU0VA9D8fUIp0ysPxWHw/e9wGSrx6Ji1cIHbKhSlIt+FWbkzMTbMeFnmYsKqe4o+3lpf+WkcBdDzE0LtlhW+WaEt6HLD8OMVVujl4UdJNZvrDAGA8ynA+SNJdlZjd5UG8mXNDkBPe33LILsJx/SYEpuyTUtG2F+QoBy+Tgc5jWZ7QLeMRluFtvKWfGARqdSmzTwKNzYoEgcOu67/vYJ1r7RmHXxXUeCFvpkQD9+Kw4HZ6ZYG3SSsorUeEJwfsErU4F7qGA9SxuW7ZNuc1ovOI0ct6yBu0YvzavqeDmqHLHc5yU5F7PFQ7Sy3LeoTOTA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, 25 Apr 2026 23:27:15 -0700 Suren Baghdasaryan wrote: > Use per-vma locks when reading /proc/pid/smaps and /proc/pid/numa_maps > similar to /proc/pid/maps to reduce contention on central mmap_lock. Was the benefit measured/measurable? Sashiko doesn't like your strchr(): https://sashiko.dev/#/patchset/20260426062718.1238437-1-surenb@google.com