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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 CB858C433E2 for ; Wed, 2 Sep 2020 11:32:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 82D552065E for ; Wed, 2 Sep 2020 11:32:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82D552065E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 217266B0037; Wed, 2 Sep 2020 07:32:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C76C6B0055; Wed, 2 Sep 2020 07:32:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0DF406B005A; Wed, 2 Sep 2020 07:32:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0171.hostedemail.com [216.40.44.171]) by kanga.kvack.org (Postfix) with ESMTP id ED63C6B0037 for ; Wed, 2 Sep 2020 07:32:06 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A74672494 for ; Wed, 2 Sep 2020 11:32:06 +0000 (UTC) X-FDA: 77217907452.25.bird44_1516881270a0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin25.hostedemail.com (Postfix) with ESMTP id 7F7621804E3A1 for ; Wed, 2 Sep 2020 11:32:06 +0000 (UTC) X-HE-Tag: bird44_1516881270a0 X-Filterd-Recvd-Size: 2593 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Wed, 2 Sep 2020 11:32:06 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E84D4B18C; Wed, 2 Sep 2020 11:32:05 +0000 (UTC) Date: Wed, 2 Sep 2020 13:32:04 +0200 From: Michal Hocko To: Vlastimil Babka Cc: Pavel Tatashin , Roman Gushchin , Bharata B Rao , "linux-mm@kvack.org" , Andrew Morton , Johannes Weiner , Shakeel Butt , Vladimir Davydov , "linux-kernel@vger.kernel.org" , Kernel Team , Yafang Shao , stable , Linus Torvalds , Sasha Levin , Greg Kroah-Hartman , David Hildenbrand Subject: Re: [PATCH v2 00/28] The new cgroup slab memory controller Message-ID: <20200902113204.GD4617@dhcp22.suse.cz> References: <20200127173453.2089565-1-guro@fb.com> <20200130020626.GA21973@in.ibm.com> <20200130024135.GA14994@xps.DHCP.thefacebook.com> <20200813000416.GA1592467@carbon.dhcp.thefacebook.com> <6469324e-afa2-18b4-81fb-9e96466c1bf3@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6469324e-afa2-18b4-81fb-9e96466c1bf3@suse.cz> X-Rspamd-Queue-Id: 7F7621804E3A1 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 02-09-20 11:53:00, Vlastimil Babka wrote: > >> > > Thread #2: ccs killer kthread > >> > > css_killed_work_fn > >> > > cgroup_mutex <- Grab this Mutex > >> > > mem_cgroup_css_offline > >> > > memcg_offline_kmem.part > >> > > memcg_deactivate_kmem_caches > >> > > get_online_mems > >> > > mem_hotplug_lock <- waits for Thread#1 to get read access And one more thing. THis has been brought up several times already. Maybe I have forgoten but why do we take hotplug locks in this path in the first place? Memory hotplug notifier takes slab_mutex so this shouldn't be really needed. -- Michal Hocko SUSE Labs