From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759118AbcBXWDp (ORCPT ); Wed, 24 Feb 2016 17:03:45 -0500 Received: from mail-qg0-f52.google.com ([209.85.192.52]:34963 "EHLO mail-qg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758930AbcBXWDQ (ORCPT ); Wed, 24 Feb 2016 17:03:16 -0500 From: Tejun Heo To: lizefan@huawei.com, hannes@cmpxchg.org Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Tejun Heo Subject: [PATCH 15/16] cgroup: make cgroup_calc_subtree_ss_mask() take @this_ss_mask Date: Wed, 24 Feb 2016 17:02:47 -0500 Message-Id: <1456351368-786-16-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1456351368-786-1-git-send-email-tj@kernel.org> References: <1456351368-786-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org cgroup_calc_subtree_ss_mask() currently takes @cgrp and @subtree_control. @cgrp is used for two purposes - to decide whether it's for default hierarchy and the mask of available subsystems. The former doesn't matter as the results are the same regardless. The latter can be specified directly through a subsystem mask. This patch makes cgroup_calc_subtree_ss_mask() perform the same calculations for both default and legacy hierarchies and take @this_ss_mask for available subsystems. @cgrp is no longer used and dropped. This is to allow using the function in contexts where available controllers can't be decided from the cgroup. v2: cgroup_refres_subtree_ss_mask() is removed by a previous patch. Updated accordingly. Signed-off-by: Tejun Heo --- kernel/cgroup.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 01792a5..744e1c6 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1308,18 +1308,17 @@ static umode_t cgroup_file_mode(const struct cftype *cft) /** * cgroup_calc_subtree_ss_mask - calculate subtree_ss_mask - * @cgrp: the target cgroup * @subtree_control: the new subtree_control mask to consider + * @this_ss_mask: available subsystems * * On the default hierarchy, a subsystem may request other subsystems to be * enabled together through its ->depends_on mask. In such cases, more * subsystems than specified in "cgroup.subtree_control" may be enabled. * * This function calculates which subsystems need to be enabled if - * @subtree_control is to be applied to @cgrp. The returned mask is always - * a superset of @subtree_control and follows the usual hierarchy rules. + * @subtree_control is to be applied while restricted to @this_ss_mask. */ -static u16 cgroup_calc_subtree_ss_mask(struct cgroup *cgrp, u16 subtree_control) +static u16 cgroup_calc_subtree_ss_mask(u16 subtree_control, u16 this_ss_mask) { u16 cur_ss_mask = subtree_control; struct cgroup_subsys *ss; @@ -1327,9 +1326,6 @@ static u16 cgroup_calc_subtree_ss_mask(struct cgroup *cgrp, u16 subtree_control) lockdep_assert_held(&cgroup_mutex); - if (!cgroup_on_dfl(cgrp)) - return cur_ss_mask; - while (true) { u16 new_ss_mask = cur_ss_mask; @@ -1342,7 +1338,7 @@ static u16 cgroup_calc_subtree_ss_mask(struct cgroup *cgrp, u16 subtree_control) * happen only if some depended-upon subsystems were bound * to non-default hierarchies. */ - new_ss_mask &= cgroup_ss_mask(cgrp); + new_ss_mask &= this_ss_mask; if (new_ss_mask == cur_ss_mask) break; @@ -3011,8 +3007,9 @@ static void cgroup_propagate_control(struct cgroup *cgrp) cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) { dsct->subtree_control &= cgroup_control(dsct); - dsct->subtree_ss_mask = cgroup_calc_subtree_ss_mask(dsct, - dsct->subtree_control); + dsct->subtree_ss_mask = + cgroup_calc_subtree_ss_mask(dsct->subtree_control, + cgroup_ss_mask(dsct)); } } -- 2.5.0