Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752379AbaGCLOy (ORCPT ); Thu, 3 Jul 2014 07:14:54 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:37967 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751128AbaGCLOx (ORCPT ); Thu, 3 Jul 2014 07:14:53 -0400 Date: Thu, 3 Jul 2014 07:14:40 -0400 From: Neil Horman To: Tejun Heo Cc: lizefan@huawei.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Weiner , Michal Hocko , Vivek Goyal , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Aristeu Rozanski , "Aneesh Kumar K.V" Subject: Re: [PATCH 4/5] cgroup: distinguish the default and legacy hierarchies when handling cftypes Message-ID: <20140703111440.GC9748@hmsreliant.think-freely.org> References: <1404345055-8196-1-git-send-email-tj@kernel.org> <1404345055-8196-5-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1404345055-8196-5-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Score: -2.9 (--) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 02, 2014 at 07:50:54PM -0400, Tejun Heo wrote: > Until now, cftype arrays carried files for both the default and legacy > hierarchies and the files which needed to be used on only one of them > were flagged with either CFTYPE_ONLY_ON_DFL or CFTYPE_INSANE. This > gets confusing very quickly and we may end up exposing interface files > to the default hierarchy without thinking it through. > > This patch makes cgroup core provide separate sets of interfaces for > cftype handling so that the cftypes for the default and legacy > hierarchies are clearly distinguished. The previous two patches > renamed the existing ones so that they clearly indicate that they're > for the legacy hierarchies. This patch adds the interface for the > default hierarchy and apply them selectively depending on the > hierarchy type. > > * cftypes added through cgroup_subsys->dfl_cftypes and > cgroup_add_dfl_cftypes() only show up on the default hierarchy. > > * cftypes added through cgroup_subsys->legacy_cftypes and > cgroup_add_legacy_cftypes() only show up on the legacy hierarchies. > > * cgroup_subsys->dfl_cftypes and ->legacy_cftypes can point to the > same array for the cases where the interface files are identical on > both types of hierarchies. > > * This makes all the existing subsystem interface files legacy-only by > default and all subsystems will have no interface file created when > enabled on the default hierarchy. Each subsystem should explicitly > review and compose the interface for the default hierarchy. > > * A boot param "cgroup__DEVEL__legacy_files_on_dfl" is added which > makes subsystems which haven't decided the interface files for the > default hierarchy to present the legacy files on the default > hierarchy so that its behavior on the default hierarchy can be > tested. As the awkward name suggests, this is for development only. > > * memcg's CFTYPE_INSANE on "use_hierarchy" is noop now as the whole > array isn't used on the default hierarchy. The flag is removed. > > Signed-off-by: Tejun Heo > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: Li Zefan > Cc: Vivek Goyal > Cc: Peter Zijlstra > Cc: Paul Mackerras > Cc: Ingo Molnar > Cc: Arnaldo Carvalho de Melo > Cc: Aristeu Rozanski > Cc: Neil Horman > Cc: Aneesh Kumar K.V Acked-by: Neil Horman -- 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/