From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 166237083C; Sun, 26 Apr 2026 19:59:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777233583; cv=none; b=LJxYrcVg1yDsWDRjbKmPli6niRLs29tPumP34hSVaRpGSNedSuWX3LjxMJU96WS7UVrAi1y2i7u5JbPZh/kc6Qo72oBjtkUTHkWkDgDwsntGsEMOzy2UF6nzM1R52/wtZb/StwWA2YZ7mwgSrv6aiVlBGLCxsNAeVFlMX+Dc988= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777233583; c=relaxed/simple; bh=sQS9ECYqFOsLOgzaV8hLZaILKmDan1UEbRlzXl0ooNw=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=jNNtN9xPSuR51tE3Bc1T0bwmxrkT4xnOB2rIcul1BUkdgGtx1TVTXIDPx2K+FaMIji5CZ1Ym5HXhj6lrpC8riIE+S77cJV28DkDkwjglEXHesjWwK1yURQXrdGJxaUTksErkKgeb8baTjY2sbMpcPJrPmpMChc4+b4QXgclX7Og= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=lZ8ZnK/Y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="lZ8ZnK/Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A566C2BCAF; Sun, 26 Apr 2026 19:59:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1777233582; bh=sQS9ECYqFOsLOgzaV8hLZaILKmDan1UEbRlzXl0ooNw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; 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) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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