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=-15.8 required=3.0 tests=BAYES_00,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 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 735EDC432BE for ; Fri, 30 Jul 2021 06:46:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57F1160F6B for ; Fri, 30 Jul 2021 06:46:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237681AbhG3Gqy (ORCPT ); Fri, 30 Jul 2021 02:46:54 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:41512 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237616AbhG3Gqx (ORCPT ); Fri, 30 Jul 2021 02:46:53 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id D83C11FDB2; Fri, 30 Jul 2021 06:46:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627627607; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9qUmfJ205mXFr7otIjDg3EOb6cwhRcnR91bxEVSEz+8=; b=CJHgYMs1CvZagyfxxxI3oeb8NfQGKjLgWO/PUNDHKEgTVynQASUGA8s6blb1AWsd2frYz2 sq1XsTCNSHlmJ3uSMeG9rQFwB7/EqyORaLPfg6BFw0nYMgKy8CG6RTKkqYsdspUVMww3GR C4dS7HVczMazNbEDpVhfBz2IHr8Eu48= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id ADEB1A3B88; Fri, 30 Jul 2021 06:46:47 +0000 (UTC) Date: Fri, 30 Jul 2021 08:46:45 +0200 From: Michal Hocko To: Miaohe Lin Cc: hannes@cmpxchg.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, shakeelb@google.com, guro@fb.com, willy@infradead.org, alexs@kernel.org, richard.weiyang@gmail.com, songmuchun@bytedance.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH 2/5] mm, memcg: narrow the scope of percpu_charge_mutex Message-ID: References: <20210729125755.16871-1-linmiaohe@huawei.com> <20210729125755.16871-3-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210729125755.16871-3-linmiaohe@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 29-07-21 20:57:52, Miaohe Lin wrote: > Since percpu_charge_mutex is only used inside drain_all_stock(), we can > narrow the scope of percpu_charge_mutex by moving it here. Makes sense and this is usually my preference as well. We used to have other caller back then so I couldn't. > Signed-off-by: Miaohe Lin Acked-by: Michal Hocko Thanks! > --- > mm/memcontrol.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 6580c2381a3e..a03e24e57cd9 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2050,7 +2050,6 @@ struct memcg_stock_pcp { > #define FLUSHING_CACHED_CHARGE 0 > }; > static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); > -static DEFINE_MUTEX(percpu_charge_mutex); > > #ifdef CONFIG_MEMCG_KMEM > static void drain_obj_stock(struct obj_stock *stock); > @@ -2209,6 +2208,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) > */ > static void drain_all_stock(struct mem_cgroup *root_memcg) > { > + static DEFINE_MUTEX(percpu_charge_mutex); > int cpu, curcpu; > > /* If someone's already draining, avoid adding running more workers. */ > -- > 2.23.0 -- Michal Hocko SUSE Labs