Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757927Ab2F0Psb (ORCPT ); Wed, 27 Jun 2012 11:48:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39396 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756740Ab2F0Psa (ORCPT ); Wed, 27 Jun 2012 11:48:30 -0400 Date: Wed, 27 Jun 2012 17:48:27 +0200 From: Michal Hocko To: Zhouping Liu Cc: linux-mm@kvack.org, Li Zefan , Tejun Heo , CAI Qian , LKML Subject: Re: memcg: cat: memory.memsw.* : Operation not supported Message-ID: <20120627154827.GA4420@tiehlicka.suse.cz> References: <2a1a74bf-fbb5-4a6e-b958-44fff8debff2@zmail13.collab.prod.int.phx2.redhat.com> <34bb8049-8007-496c-8ffb-11118c587124@zmail13.collab.prod.int.phx2.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <34bb8049-8007-496c-8ffb-11118c587124@zmail13.collab.prod.int.phx2.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1624 Lines: 41 On Tue 26-06-12 23:49:15, Zhouping Liu wrote: > hi, all > > when I used memory cgroup in latest mainline, the following error occurred: > > # mount -t cgroup -o memory xxx /cgroup/ > # ll /cgroup/memory.memsw.* > -rw-r--r--. 1 root root 0 Jun 26 23:17 /cgroup/memory.memsw.failcnt > -rw-r--r--. 1 root root 0 Jun 26 23:17 /cgroup/memory.memsw.limit_in_bytes > -rw-r--r--. 1 root root 0 Jun 26 23:17 /cgroup/memory.memsw.max_usage_in_bytes > -r--r--r--. 1 root root 0 Jun 26 23:17 /cgroup/memory.memsw.usage_in_bytes > # cat /cgroup/memory.memsw.* > cat: /cgroup/memory.memsw.failcnt: Operation not supported > cat: /cgroup/memory.memsw.limit_in_bytes: Operation not supported > cat: /cgroup/memory.memsw.max_usage_in_bytes: Operation not supported > cat: /cgroup/memory.memsw.usage_in_bytes: Operation not supported > > I'm confusing why it can't read memory.memsw.* files. Those files are exported if CONFIG_CGROUP_MEM_RES_CTLR_SWAP=y even if the feature is turned off when any attempt to open the file returns EOPNOTSUPP which is exactly what you are seeing. This is a deliberate decision see: b6d9270d (memcg: always create memsw files if CONFIG_CGROUP_MEM_RES_CTLR_SWAP). Does this help to explain your problem? Do you actually see any problem with this behavior? Thanks -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/