From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D378DCCFA18 for ; Wed, 12 Nov 2025 02:11:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3AB018E0009; Tue, 11 Nov 2025 21:11:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 382B08E0003; Tue, 11 Nov 2025 21:11:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2BF7D8E0009; Tue, 11 Nov 2025 21:11:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 1A22F8E0003 for ; Tue, 11 Nov 2025 21:11:27 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id A2B1312D05C for ; Wed, 12 Nov 2025 02:11:26 +0000 (UTC) X-FDA: 84100328172.08.809E22D Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) by imf18.hostedemail.com (Postfix) with ESMTP id 2C7821C0003 for ; Wed, 12 Nov 2025 02:11:22 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=A7XRRi4j; spf=pass (imf18.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762913485; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=uriJ/UZtbFIWJHYtkqAM7/7gRRqxwaWIv7KjAJwxh2s=; b=hqDa7EJTJvXCUqoJyU2m1dPwN8hi34zFl1Qd5V+J3GUWzHNSyfeXS3vV7iOoIRwMDqsGS4 CO18g3KudrdM8sHt4+gx3KdR+xv5xSv3LsqvaQiAAgy7tNtbRhuLgXlr0D93UGjSJQn9VH v8Yrl/Hdm0N01YI1LalM2xFDRtjeVKk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762913485; a=rsa-sha256; cv=none; b=oGTKs97NRN7Gbn2nNbHfaia8gjBNQojjyBjUMCKwG1wb6Rr/FrHRVKRXCmA1SAs5CwmYhN uIDAkyDJf2w8ILj3Rq69B2XDbQ6+YrFQmVNRTZc0TLIRcTdBFdrjJ8P6RatHyh8zbhF+Gx CpoIn5MFCtUgG7cgXCVCKrA2qY3kHBE= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=A7XRRi4j; spf=pass (imf18.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1762913480; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uriJ/UZtbFIWJHYtkqAM7/7gRRqxwaWIv7KjAJwxh2s=; b=A7XRRi4jm9+2dng+brC/ULaeX9wZNMw/VzLlf/tyUGMqCUfZ2beqnlyFDHJ5onqOe9qT/x +xVpymK38zhN1SdT+9T6nvNkJhJWwRUumKKTdfvjlk+gOa4GWGWTPF5Gmf3ZhCEuJaIj/S 4caHjsnL4DfoYVhD3xw/wxg9bXoNT3k= Date: Wed, 12 Nov 2025 10:11:11 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 0/4] memcg: cleanup the memcg stats interfaces To: Shakeel Butt Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Harry Yoo , Vlastimil Babka , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team , Andrew Morton References: <20251110232008.1352063-1-shakeel.butt@linux.dev> <0618ea79-fed3-4d4d-9573-2be49de728cf@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: 2C7821C0003 X-Stat-Signature: naaj8rh8e1sgste6pdzqpdiupj7dfaes X-HE-Tag: 1762913482-94916 X-HE-Meta: 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 IgUXkJur swESt/LbRWMplkzmDiN1siswxu8JgIwMjlR8QLaegt19eTAOM4oKKk20p36UpDoZUXbL/bsSs1gg22W82qtbmlhRgQE+Y8WOEfk6ecpIw12ytUsPZoVcw13yogxcPj8CB6JSEiXRXdEl9RuNSv4almsQiuAFfbO5FLcSSbJ317aMn0yAymDICPwt20na4GX+ru5rsJCaHE01s94r5GgBRmX/47A== 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 11/12/25 12:45 AM, Shakeel Butt wrote: > On Tue, Nov 11, 2025 at 04:36:14PM +0800, Qi Zheng wrote: >> Hi Shakeel, >> >> On 11/11/25 7:20 AM, Shakeel Butt wrote: >>> The memcg stats are safe against irq (and nmi) context and thus does not >>> require disabling irqs. However for some stats which are also maintained >>> at node level, it is using irq unsafe interface and thus requiring the >>> users to still disables irqs or use interfaces which explicitly disables >>> irqs. Let's move memcg code to use irq safe node level stats function >>> which is already optimized for architectures with HAVE_CMPXCHG_LOCAL >>> (all major ones), so there will not be any performance penalty for its >>> usage. >> >> Generally, places that call __mod_lruvec_state() also call >> __mod_zone_page_state(), and it also has the corresponding optimized >> version (mod_zone_page_state()). It seems necessary to clean that up >> as well, so that those disabling-IRQs that are only used for updating >> vmstat can be removed. > > I agree, please take a stab at that. OK, will do.