From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 019FD2C0285; Wed, 27 May 2026 01:49:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779846587; cv=none; b=R94uwQs4UcloEW3kza4lvgvjnG8RXNfwK9m7Ukt3pVRGgzRozSz6pHe9RvcYGhKeJYwV284e1bdgrLkxXeR4nYF1Qq+cUSUp3qfz6ODoBrMGjE/mBQ+9Nc1ZcIPS6vcxDtIIilgE2dAfdZLiBW5/MRGvR+hh0GcGZBogZf55zHE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779846587; c=relaxed/simple; bh=OnRb35zsOkFRW/CWmv18Wy/NJmcehYUJoAIUg83Y5G0=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=f18Mh5WqHUizQLAJCywcEzJjVGbvcOPq4pOIBwxhYSWXx5KLUASfkRaImxzs3Ki109SRGyecRIpnRtbbBmQV7XwoEdkhlCP6lWCm58YzcwT5Bx4Q8qo/9k4E7VduPWrHuKE2vI2xu50uGw8nkOG4WEjC1yl9gRUuenCy161cUpM= 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=QJeYrvmY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="QJeYrvmY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F42E1F000E9; Wed, 27 May 2026 01:49:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1779846585; bh=RQHn0lIESMVrKtDroCt10TOS7riOoU6PCqbNq2RdkAw=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QJeYrvmYIXlRgXJqbx2m87Z2F6eVrL4d6nmkeXmTxP+bjQnHFWIWAi+Maiat5XOcW tO1AzZwFe4aVT2grsG0L1uOza0ONm543/qk70VhANXMcH82Q+9Yxp/XNMr1botqiD0 QG3usvJtyuOKWb2Hbiirgtj5Lo1s2kEvJi/RyGnk= Date: Tue, 26 May 2026 18:49:44 -0700 From: Andrew Morton To: Suren Baghdasaryan Cc: "David Hildenbrand (Arm)" , liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, 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: <20260526184944.18c28d6980fd29ff12fbbe22@linux-foundation.org> In-Reply-To: References: <20260426062718.1238437-1-surenb@google.com> <0ce6071b-0c99-4119-9ab4-a2d9c00b99a8@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@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 Thu, 21 May 2026 08:16:01 -0700 Suren Baghdasaryan wrote: > > > It might be but the point of this patchset (and the previous one that > > > made a similar change for /proc/pid/maps) is to reduce mmap_lock > > > contention, not to speed up the read operation, which is not a > > > performance critical part. > > > > Well, this interface has been around .. forever, so if there is a noticeable > > change in performance it should be called out. > > Sorry, I missed your reply. I'll see if I can adopt Paul's test for > /proc/pid/maps [1] for benchmarking smaps but I would expect similar > results as was reported in [2]. How's it coming along ;) > [1] https://github.com/paulmckrcu/proc-mmap_sem-test > [2] https://lore.kernel.org/all/20250719182854.3166724-1-surenb@google.com/ I've moved this series to the tail of mm-unstable to permit more time.