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 X-Spam-Level: X-Spam-Status: No, score=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87797C4338F for ; Thu, 29 Jul 2021 14:39:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DB1F60F6F for ; Thu, 29 Jul 2021 14:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237441AbhG2Ojb (ORCPT ); Thu, 29 Jul 2021 10:39:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236285AbhG2Oj0 (ORCPT ); Thu, 29 Jul 2021 10:39:26 -0400 Received: from mail-lj1-x232.google.com (mail-lj1-x232.google.com [IPv6:2a00:1450:4864:20::232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77426C061765 for ; Thu, 29 Jul 2021 07:39:22 -0700 (PDT) Received: by mail-lj1-x232.google.com with SMTP id l17so7880761ljn.2 for ; Thu, 29 Jul 2021 07:39:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pQ+TosWiDAdG8+90eQclOC0l7J20f+GG4ER7QwTBKX8=; b=R23L4N03E0Cp8DvPNPKl1idmWh2CJdaYEmaLa1zbfrqP6vbUf+kVIxIr+waUl74KJ7 Mphdxreoppmm+jRPzPzsh1BxrZm8LVudhznf1T4QIzuK2yPi+akMMez82h2jumMlbVBf S4s7yiBKeS5xYqWyj6/0VB0Gc5h/lkfbSVQ8/wSDflor4uoM7saLwFNOPaGtfgypCOj/ +WIjAxfYsT6tTBO/q53IY7HCwDcgVv78qaKosze2J5wD59XRmrOEtTa4h7EmF5Pf5cK0 nkmiVrgBr2zJPDiZ0MD0JZ5mxei1/97cIXhT5vYsbRVqwrZO7WrhQf5r9ywwwTopzLvU jR6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=pQ+TosWiDAdG8+90eQclOC0l7J20f+GG4ER7QwTBKX8=; b=rVkNYNSXCKB79dApVm8gCOOu6Ke2Nc8aIVTTU7VteeDwCfRyCXlg6xtNC9NQP/8vLK 0Z/u5RCwv7PAiFAQoukBFWypijNJNdc9ZOUBQ412sG/9vewVCaTHca28/sjIc06nw/VK aDdPMxaB3SdauUo8ON27+0VOoHgwPNGb+tEpHIZfJ/5IpddiVpYYBRjvMhmUP0WX1uMu 2vUrSxVBLZAsJCfGs+/ndCjityAYMkCdk4WL+cfeRM8fAWd+AlYNAGr0WjUZvBNA+8LH T3VJy0Kr48b5aRQ0XLfC9cFlA2pQd+QqwZFv7243Pkeqito/NqVdvNrIQW3FHLq8QldX ifYQ== X-Gm-Message-State: AOAM530TQZLWHKgFknmz5/LfJguAZ5Vx/pdaXMtJKCfCSoOoEH6x2KZR xDoy3MKIJCAbPDeX16we7emXWAbffNnbxRNIYecqIg== X-Google-Smtp-Source: ABdhPJysPj8T1T/jC1N62guQJtz/h9nWJSh3QUau+BzFLvn4bSnqGN64gK1+jXKEM+irMoznNKLcgVOnxOJpvkYACmY= X-Received: by 2002:a2e:85d7:: with SMTP id h23mr3111083ljj.279.1627569560514; Thu, 29 Jul 2021 07:39:20 -0700 (PDT) MIME-Version: 1.0 References: <20210729125755.16871-1-linmiaohe@huawei.com> <20210729125755.16871-6-linmiaohe@huawei.com> In-Reply-To: <20210729125755.16871-6-linmiaohe@huawei.com> From: Shakeel Butt Date: Thu, 29 Jul 2021 07:39:08 -0700 Message-ID: Subject: Re: [PATCH 5/5] mm, memcg: always call __mod_node_page_state() with preempt disabled To: Miaohe Lin Cc: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Roman Gushchin , Matthew Wilcox , alexs@kernel.org, Wei Yang , Muchun Song , Linux MM , LKML , Cgroups Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 29, 2021 at 5:58 AM Miaohe Lin wrote: > > We should always ensure __mod_node_page_state() is called with preempt > disabled or percpu ops may manipulate the wrong cpu when preempt happened. > > Fixes: b4e0b68fbd9d ("mm: memcontrol: use obj_cgroup APIs to charge kmem pages") > Signed-off-by: Miaohe Lin > --- > mm/memcontrol.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 70a32174e7c4..616d1a72ece3 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -697,8 +697,8 @@ void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx, > memcg = page_memcg(head); > /* Untracked pages have no memcg, no lruvec. Update only the node */ > if (!memcg) { > - rcu_read_unlock(); > __mod_node_page_state(pgdat, idx, val); > + rcu_read_unlock(); This rcu is for page_memcg. The preemption and interrupts are disabled across __mod_lruvec_page_state(). > return; > } > > -- > 2.23.0 >