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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 98D4FC43603 for ; Wed, 18 Dec 2019 04:51:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68B402176D for ; Wed, 18 Dec 2019 04:51:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576644715; bh=Vl2hyvtu7Iviw5OO/kfGHA1hcWxfcadVdsZrNSk66dE=; h=Date:From:To:Subject:In-Reply-To:List-ID:From; b=Krl1WYRQgNpj0/EmkQi3Hg/HvWN7sEb+Y8W+xzi3Mrq4IHYYoUHP/aYZIM+HyHd2a SRV4ox9ypeV8L848QMTVgJQT/TNec2HiuPO0PI5ExME1znTXCEYS/9CV9h/S8H2yXP k17/GFUiLX3lb4OWnegtLzxOvVQUrd6onReGiiKE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726569AbfLREvy (ORCPT ); Tue, 17 Dec 2019 23:51:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:35306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726518AbfLREvy (ORCPT ); Tue, 17 Dec 2019 23:51:54 -0500 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5373921582; Wed, 18 Dec 2019 04:51:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576644713; bh=Vl2hyvtu7Iviw5OO/kfGHA1hcWxfcadVdsZrNSk66dE=; h=Date:From:To:Subject:In-Reply-To:From; b=gSOXi81HNbOMQlPe4599bknzdcu5VEtlFBca3FzYiDWDmwCLD/wNzt7PV28XUkKQg vsYS5Zj9XCU2Y17aYEDhG8tjTvg05LKAzEMp37x55IZK3YjFQOZ5/0HzMRBEtmgZdb s9S9DWaYqePecyFg3Shsb6cALxxsZo1Cgjl4P2dU= Date: Tue, 17 Dec 2019 20:51:52 -0800 From: Andrew Morton To: akpm@linux-foundation.org, guro@fb.com, hannes@cmpxchg.org, ktkhai@virtuozzo.com, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, shakeelb@google.com, stable@vger.kernel.org, torvalds@linux-foundation.org, yang.shi@linux.alibaba.com Subject: [patch 5/6] mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG Message-ID: <20191218045152.iNg-dg4P2%akpm@linux-foundation.org> In-Reply-To: <20191217205020.6e2eaefc78710ec646e99aa9@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yang Shi Subject: mm: vmscan: protect shrinker idr replace with CONFIG_MEMCG Since commit 0a432dcbeb32edc ("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. And in the CONFIG_MEMCG && CONFIG_SLOB case, shrinker_idr contains only shrinker, and it is deferred_split_shrinker. But it is never actually called, since idr_replace() is never compiled due to the wrong #ifdef. The deferred_split_shrinker all the time is staying in half-registered state, and it's never called for subordinate mem cgroups. Link: http://lkml.kernel.org/r/1575486978-45249-1-git-send-email-yang.shi@linux.alibaba.com Fixes: 0a432dcbeb32 ("mm: shrinker: make shrinker not depend on memcg kmem") Signed-off-by: Yang Shi Reviewed-by: Kirill Tkhai Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Shakeel Butt Cc: Roman Gushchin Cc: [5.4+] Signed-off-by: Andrew Morton --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmscan.c~mm-vmscan-protect-shrinker-idr-replace-with-config_memcg +++ a/mm/vmscan.c @@ -387,7 +387,7 @@ void register_shrinker_prepared(struct s { 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 _