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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D414AC2BD09 for ; Thu, 5 Dec 2019 09:43:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4E9E2464E for ; Thu, 5 Dec 2019 09:43:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575539027; bh=Syig5wrWKP0Sn3hNKXEWvCZjSSInuJM0x3UjVn5ZGzo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=MM/VXw261eTXn/unchFQ8lPyEPvn+3qZFu/AieAb973k0Up0CN7YYCSAlzZ/pK0Yd PPoSwqA5RdmMj4RF5yUKhU59RpeZPCjUmkB/6R68vwlGW5x9H1SbBTf/y134bA82oH c6WmoXP0MP4n/ijps0C8DzM9lXD53PhCkK4iQY28= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729163AbfLEJnq (ORCPT ); Thu, 5 Dec 2019 04:43:46 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:34931 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726177AbfLEJnp (ORCPT ); Thu, 5 Dec 2019 04:43:45 -0500 Received: by mail-wr1-f65.google.com with SMTP id g17so2686038wro.2 for ; Thu, 05 Dec 2019 01:43:44 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=x2NY4RsN9EIpsZSpxJClccspscZUZls+ET6N9cgE4kc=; b=JHRpcgaAXJl8h313Awg0WaISpsF+N9C2KkbwEFDf57NhTIZIn2HDM5MvDpA4C0tHMV Gyjr/5605XS8+KEJMUc5GiQLNY/wOAetkVix7JqlhNF8d5Cg880hOoGWMcw7u2MUPrtO lEkbXxXjUqNNVgmcOxysxe/9doni4aNVFZFNYCD5gHftOUfeZMkt4grSfVsXRFiyGGti fGu0GxMb2WQ8cP9X3T+FbSJ6Gnm0Kc/f1BKun06EecBFaIxaWrVvaBdTnQtFoJCRpq+n mENWVlmX7v6uIZnhHRve6+5dqayhtR5oyqRWMqua3dJ4s6b+iiss9RjlWF+/04bf5Whc dPLw== X-Gm-Message-State: APjAAAWUKpbU/9bomZYUy5FzbrFhpLM/GiRvuICX1FnBT8ED5zq1m4IZ DUcnAqEFaOYyJmXGqSgPAr8= X-Google-Smtp-Source: APXvYqwoTreIVWXx2AHtCZXbwx/4wKo9v1WDlJAhlsuvcN/CjfFVnQDFjX0eJwsccVPt4FeM07XHgg== X-Received: by 2002:adf:8041:: with SMTP id 59mr8603077wrk.257.1575539023465; Thu, 05 Dec 2019 01:43:43 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id 72sm12036760wrl.73.2019.12.05.01.43.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Dec 2019 01:43:42 -0800 (PST) Date: Thu, 5 Dec 2019 10:43:41 +0100 From: Michal Hocko To: Kirill Tkhai Cc: Yang Shi , hannes@cmpxchg.org, shakeelb@google.com, guro@fb.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG Message-ID: <20191205094341.GC28317@dhcp22.suse.cz> References: <1575486978-45249-1-git-send-email-yang.shi@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 05-12-19 11:23:28, Kirill Tkhai wrote: > On 04.12.2019 22:16, Yang Shi wrote: > > Since commit 0a432dcbeb32edcd211a5d8f7847d0da7642a8b4 ("mm: shrinker: > > make shrinker not depend on memcg kmem"), shrinkers' idr is protected by > > CONFIG_MEMCG instead of CONFIG_MEMCG_KMEM, so it makes no sense to > > protect shrinker idr replace with CONFIG_MEMCG_KMEM. > > > > Cc: Kirill Tkhai > > Cc: Johannes Weiner > > Cc: Michal Hocko > > Cc: Shakeel Butt > > Cc: Roman Gushchin > > Signed-off-by: Yang Shi > > It looks like that in CONFIG_SLOB case we do not even call some shrinkers > for subordinate mem cgroups (i.e., we don't call deferred_split_shrinker), > since they never become completely registered. > > Fixes: 0a432dcbeb32edcd211a5d8f7847d0da7642a8b4 ("mm: shrinker: make shrinker not depend on memcg kmem") I am confused. Why the Fixes tag? Nothing should be really broken with KMEM config guard right? This is a mere clean up AFAICS. > Reviewed-by: Kirill Tkhai > > > --- > > mm/vmscan.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index ee4eecc..e7f10c4 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -422,7 +422,7 @@ void register_shrinker_prepared(struct shrinker *shrinker) > > { > > down_write(&shrinker_rwsem); > > list_add_tail(&shrinker->list, &shrinker_list); > > -#ifdef CONFIG_MEMCG_KMEM > > +#ifdef CONFIG_MEMCG > > if (shrinker->flags & SHRINKER_MEMCG_AWARE) > > idr_replace(&shrinker_idr, shrinker, shrinker->id); > > #endif > > -- Michal Hocko SUSE Labs