From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 913BE4A3C; Mon, 2 Feb 2026 08:54:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770022444; cv=none; b=YYiApgrTtOCS9Y9b7o+/omLYEOz7nymXA9ESzVHWS+xEMmosNizAJ0+BKyto5jYCIQYTIHe31D4v82z/TiudcVVlq4UsYSWuF2d1gUT9OceurtTrObJ6qft1L0zCWHR9EAOsz1DCK39xh0Uk9/gpAz679CAaVf0BVLjr16nqrHQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770022444; c=relaxed/simple; bh=L5BozPIX+bclBxZ7KoKXqotYg7/JAXk/wQVKWVmv0eU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nfWbacuWAnyi8R9Zt3z6yXu8Jd+/KEf4GnDHHt2v9g8p4oKgD3V7YdyXQBM6a4qcIkySsw7uLdIOi6jXTVFAnhnzZItNSSZWY25GwktypWEKACGasrlyROQHXWvz0xBnQr8fS+ToV6u32/PaB0J9GWIPcvspevO3txY+9yq7JoQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 44738339; Mon, 2 Feb 2026 00:53:55 -0800 (PST) Received: from [10.164.18.75] (unknown [10.164.18.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CC54E3F740; Mon, 2 Feb 2026 00:53:57 -0800 (PST) Message-ID: <05aec69b-8e73-49ac-aa89-47b371fb6269@arm.com> Date: Mon, 2 Feb 2026 14:23:54 +0530 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/4] memcg: use mod_node_page_state to update stats To: Shakeel Butt Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Harry Yoo , Qi Zheng , Vlastimil Babka , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team References: <20251110232008.1352063-1-shakeel.butt@linux.dev> <20251110232008.1352063-2-shakeel.butt@linux.dev> <1052a452-9ba3-4da7-be47-7d27d27b3d1d@arm.com> <2638bd96-d8cc-4733-a4ce-efdf8f223183@arm.com> <51819ca5a15d8928caac720426cd1ce82e89b429@linux.dev> Content-Language: en-US From: Dev Jain In-Reply-To: <51819ca5a15d8928caac720426cd1ce82e89b429@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 02/02/26 10:24 am, Shakeel Butt wrote: >>>> Hello Shakeel, >>>> >>>> We are seeing a regression in micromm/munmap benchmark with this patch, on arm64 - >>>> the benchmark mmmaps a lot of memory, memsets it, and measures the time taken >>>> to munmap. Please see below if my understanding of this patch is correct. >>>> >>> Thanks for the report. Are you seeing regression in just the benchmark >>> or some real workload as well? Also how much regression are you seeing? >>> I have a kernel rebot regression report [1] for this patch as well which >>> says 2.6% regression and thus it was on the back-burner for now. I will >>> take look at this again soon. >>> >> The munmap regression is ~24%. Haven't observed a regression in any other >> benchmark yet. > Please share the code/benchmark which shows such regression, also if you can > share the perf profile, that would be awesome. https://gitlab.arm.com/tooling/fastpath/-/blob/main/containers/microbench/micromm.c You can run this with ./micromm 0 munmap 10 Don't have a perf profile, I measured the time taken by above command, with and without the patch.