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 9B134C433DB for ; Mon, 8 Mar 2021 21:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C21564F96 for ; Mon, 8 Mar 2021 21:12:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230250AbhCHVML (ORCPT ); Mon, 8 Mar 2021 16:12:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231423AbhCHVLv (ORCPT ); Mon, 8 Mar 2021 16:11:51 -0500 Received: from mail-lf1-x12a.google.com (mail-lf1-x12a.google.com [IPv6:2a00:1450:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D9D3C06175F for ; Mon, 8 Mar 2021 13:11:51 -0800 (PST) Received: by mail-lf1-x12a.google.com with SMTP id k9so23298940lfo.12 for ; Mon, 08 Mar 2021 13:11:51 -0800 (PST) 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=a5NhGk9Ze+SQuaoK4vhROcGQTDpMP/SN4w2gJyziaiY=; b=QqI8pLqRynx4LJTYrKtttzBwMys2s8NV+Q05Mdn2do/eFnqWkiYXU9aAux/oSxBh00 kCtcRrWovvyfev3yY8Ax6y7EcxMeQRRLm5cWV9+wckxu+xyWHO7E62N+KFS68jkWyvC+ q6LcES7tS87j7CAWXnpsEWZJciZVVXhD8bc+6sz4GHtflsys1rX1v7g0wEUAhPTxCkEr nxIOWtyXlQIYUnMjG/JAkilvn/LeZPFaDtO8VClOeh3G1qXs1RAKEsDSorVbSUreI0+t J4nsJYoc/fpUfLXDXTEETYEs7j/Kwm0h/toueZtbyfBHdx3/vUwAczsvZXuSvAFvaypw nB1w== 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=a5NhGk9Ze+SQuaoK4vhROcGQTDpMP/SN4w2gJyziaiY=; b=g82Oj5zc+S/gqRNhIhoDPN0PazIOZhntVHGbFAmxYwf6DFY1wZZ6ysfrT/jfSssMZD SqbfkMUAWBTJgJHqayijhcwLhj6s3yALMGA6H1ev99O53CJTzF1BHI+F7NZWp67K1NCq X1nIqthILJj1hYwwaAr7Mt016+oD28IDjjSmyecMnEi/SO1ipUl6Q6UKUgIwEtmcz/xL 16c8Hf1PJ/VMsT/NO2kVTWp7WaPF68EwoIReW1QQDyaSJ2B2w8ByB4cmS1WysP5Qw6Ct B6T+IRWkWeylF93FJB6R0GA8FY5Xwei+7inUUTASeRfbt1OKjiyrhcfxRbCGf67gRbqm PViQ== X-Gm-Message-State: AOAM531NOAo1HR8rXQ81AO0LQ1CotbEvL888VikkSN5oKZeCkBDUv9sy 1qLyNEP7zBcBflP6t7lnJ69je8BYkvZlzqklaoONww== X-Google-Smtp-Source: ABdhPJy9O6D6xeUx2gKio0xVXoVq5jK1dTwDHx9t1Qg5OnfI5dRQjBSQvmy/loj2IBoqOUXpmd9OOwNLkFvmQuB9SpQ= X-Received: by 2002:a05:6512:6c6:: with SMTP id u6mr15152395lff.347.1615237909692; Mon, 08 Mar 2021 13:11:49 -0800 (PST) MIME-Version: 1.0 References: <20210217001322.2226796-1-shy828301@gmail.com> <20210217001322.2226796-6-shy828301@gmail.com> In-Reply-To: From: Shakeel Butt Date: Mon, 8 Mar 2021 13:11:35 -0800 Message-ID: Subject: Re: [v8 PATCH 05/13] mm: vmscan: use kvfree_rcu instead of call_rcu To: Yang Shi Cc: Roman Gushchin , paulmck@kernel.org, Kirill Tkhai , Vlastimil Babka , Dave Chinner , Johannes Weiner , Michal Hocko , Andrew Morton , Linux MM , linux-fsdevel , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Mar 8, 2021 at 12:22 PM Yang Shi wrote: > > On Mon, Mar 8, 2021 at 8:49 AM Roman Gushchin wrote: > > > > On Sun, Mar 07, 2021 at 10:13:04PM -0800, Shakeel Butt wrote: > > > On Tue, Feb 16, 2021 at 4:13 PM Yang Shi wrote: > > > > > > > > Using kvfree_rcu() to free the old shrinker_maps instead of call_rcu(). > > > > We don't have to define a dedicated callback for call_rcu() anymore. > > > > > > > > Signed-off-by: Yang Shi > > > > --- > > > > mm/vmscan.c | 7 +------ > > > > 1 file changed, 1 insertion(+), 6 deletions(-) > > > > > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > > > index 2e753c2516fa..c2a309acd86b 100644 > > > > --- a/mm/vmscan.c > > > > +++ b/mm/vmscan.c > > > > @@ -192,11 +192,6 @@ static inline int shrinker_map_size(int nr_items) > > > > return (DIV_ROUND_UP(nr_items, BITS_PER_LONG) * sizeof(unsigned long)); > > > > } > > > > > > > > -static void free_shrinker_map_rcu(struct rcu_head *head) > > > > -{ > > > > - kvfree(container_of(head, struct memcg_shrinker_map, rcu)); > > > > -} > > > > - > > > > static int expand_one_shrinker_map(struct mem_cgroup *memcg, > > > > int size, int old_size) > > > > { > > > > @@ -219,7 +214,7 @@ static int expand_one_shrinker_map(struct mem_cgroup *memcg, > > > > memset((void *)new->map + old_size, 0, size - old_size); > > > > > > > > rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_map, new); > > > > - call_rcu(&old->rcu, free_shrinker_map_rcu); > > > > + kvfree_rcu(old); > > > > > > Please use kvfree_rcu(old, rcu) instead of kvfree_rcu(old). The single > > > param can call synchronize_rcu(). > > > > Oh, I didn't know about this difference. Thank you for noticing! > > BTW, I think I could keep you and Kirill's acked-by with this change > (using two params form kvfree_rcu) since the change seems trivial. Once you change, you can add: Reviewed-by: Shakeel Butt