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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 8BF41C433DB for ; Wed, 10 Feb 2021 01:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EF7564DD1 for ; Wed, 10 Feb 2021 01:10:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234581AbhBJBKM (ORCPT ); Tue, 9 Feb 2021 20:10:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234944AbhBJBIB (ORCPT ); Tue, 9 Feb 2021 20:08:01 -0500 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82F5CC061574; Tue, 9 Feb 2021 17:07:20 -0800 (PST) Received: by mail-ej1-x633.google.com with SMTP id p20so959940ejb.6; Tue, 09 Feb 2021 17:07:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ePOOgJ1bRE7sZrw4203J7YVw7l2PTtMtobAvSfxZsE8=; b=GyyJJ/YjmAijxmg74wofh+2bQ0XakpFCm424T5jbHcOLM/qUrPvmEQk6wOQ95qlWS9 Gk1QfPaSXbUX9cSP16QgEP68Hgo+wRKKpKKq+syClxOwTlQnrqJWaH9qoHcFeT9/3StP ZrxNd7cQuiRmYgcy1pHgJ3HY7O/xkSs50bH0XDWHx7rIzorLmS8+Tq8UQp00IlfAqzs2 p3elJnl+n5+s+UIYGcE5mBa9w885JXbgitP5XAjKPAYnD1M3BzsxHDifE3AXa5fNmKk2 UEZOoiP4L0534FaamPfN6OaulnBllYmpYYKhyhXUYsC/f/LtQU/Kwt9q9A7KQlxNCUU2 hWzQ== 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=ePOOgJ1bRE7sZrw4203J7YVw7l2PTtMtobAvSfxZsE8=; b=UeH+RbCDs5fbkSat5kaCBEnwwLJ74fG2015lmSWOrYRhc9BrznECdd/WB9Tqq1wuIZ QGaZJvTsGBJhGE7fCviUb7QfX0VXaYIEkcz/brxnXQdvg24LLBsOCRv5b/tb448I8AIm fxhYno9XbQBTVjMdu/eq6qZpGi8K9h/8WZfBR6nHZPMUZCjOA0p6MOVw2pBBJ9hl6feQ sylDmaLtultON727i11ms7kIEN26WqGuoU3cF8pQF8FwpF40pjoysjPl30++hJez9M5N xGWZgtHoM8IwiUj21aQg4NKwHZALPIBuc5B0RBktThBn55XSAHch93CnJN57ck6Zc9V7 9Igg== X-Gm-Message-State: AOAM530sVE52utf3LeW5a+IbOyojHzzhTIH3m578eVoGQ+nsXreEml2c qiyN+GWhOztTiosCLYEoBm47jDZ5SEFMO5e3EA0= X-Google-Smtp-Source: ABdhPJw4DItb779I2iVr2ra7DPTmnwUuXp3XWcNxJXP4T0tQgBy4M3uYGgqeOu3ilbXbTM9VyEvJJ6VdPOIB+WjhakQ= X-Received: by 2002:a17:906:2583:: with SMTP id m3mr383234ejb.499.1612919239346; Tue, 09 Feb 2021 17:07:19 -0800 (PST) MIME-Version: 1.0 References: <20210209174646.1310591-1-shy828301@gmail.com> <20210209174646.1310591-7-shy828301@gmail.com> <20210210002218.GJ524633@carbon.DHCP.thefacebook.com> In-Reply-To: <20210210002218.GJ524633@carbon.DHCP.thefacebook.com> From: Yang Shi Date: Tue, 9 Feb 2021 17:07:07 -0800 Message-ID: Subject: Re: [v7 PATCH 06/12] mm: vmscan: add shrinker_info_protected() helper To: Roman Gushchin Cc: Kirill Tkhai , Vlastimil Babka , Shakeel Butt , Dave Chinner , Johannes Weiner , Michal Hocko , Andrew Morton , Linux MM , Linux FS-devel Mailing List , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Feb 9, 2021 at 4:22 PM Roman Gushchin wrote: > > On Tue, Feb 09, 2021 at 09:46:40AM -0800, Yang Shi wrote: > > The shrinker_info is dereferenced in a couple of places via rcu_dereference_protected > > with different calling conventions, for example, using mem_cgroup_nodeinfo helper > > or dereferencing memcg->nodeinfo[nid]->shrinker_info. And the later patch > > will add more dereference places. > > > > So extract the dereference into a helper to make the code more readable. No > > functional change. > > > > Signed-off-by: Yang Shi > > --- > > mm/vmscan.c | 15 ++++++++++----- > > 1 file changed, 10 insertions(+), 5 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 9436f9246d32..273efbf4d53c 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -190,6 +190,13 @@ static int shrinker_nr_max; > > #define NR_MAX_TO_SHR_MAP_SIZE(nr_max) \ > > (DIV_ROUND_UP(nr_max, BITS_PER_LONG) * sizeof(unsigned long)) > > > > +static struct shrinker_info *shrinker_info_protected(struct mem_cgroup *memcg, > > + int nid) > > +{ > > + return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info, > > + lockdep_is_held(&shrinker_rwsem)); > > +} > > + > > > I'd probably drop the "protected" suffix (because there is no unprotected version, > right?). No, actually there is one "unprotected" call in set_shrinker_bit(). > > Other than that LGTM. > > Acked-by: Roman Gushchin