From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757238AbcBWDr4 (ORCPT ); Mon, 22 Feb 2016 22:47:56 -0500 Received: from mail-qg0-f51.google.com ([209.85.192.51]:33210 "EHLO mail-qg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757054AbcBWDqG (ORCPT ); Mon, 22 Feb 2016 22:46:06 -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 12/12] cgroup: make cgroup_calc_subtree_ss_mask() take @this_ss_mask Date: Mon, 22 Feb 2016 22:45:46 -0500 Message-Id: <1456199146-14765-13-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1456199146-14765-1-git-send-email-tj@kernel.org> References: <1456199146-14765-1-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. This patch also drops cgroup_refresh_subtree_ss_mask(). It's a thin wrapper which saves a bit of typing but the saving is pretty small and planned changes will make its uses look inconsistent compared to usages which don't update cgroups. Signed-off-by: Tejun Heo --- kernel/cgroup.c | 42 ++++++++++++++++-------------------------- 1 file changed, 16 insertions(+), 26 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a1f82fa..15461c7 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1301,18 +1301,17 @@ 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; @@ -1320,9 +1319,6 @@ 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; @@ -1335,7 +1331,7 @@ 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; @@ -1346,19 +1342,6 @@ static u16 cgroup_calc_subtree_ss_mask(struct cgroup *cgrp, u16 subtree_control) } /** - * cgroup_refresh_subtree_ss_mask - update subtree_ss_mask - * @cgrp: the target cgroup - * - * Update @cgrp->subtree_ss_mask according to the current - * @cgrp->subtree_control using cgroup_calc_subtree_ss_mask(). - */ -static void cgroup_refresh_subtree_ss_mask(struct cgroup *cgrp) -{ - cgrp->subtree_ss_mask = - cgroup_calc_subtree_ss_mask(cgrp, cgrp->subtree_control); -} - -/** * cgroup_kn_unlock - unlocking helper for cgroup kernfs methods * @kn: the kernfs_node being serviced * @@ -1592,7 +1575,9 @@ static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) src_root->subsys_mask &= ~(1 << ssid); scgrp->subtree_control &= ~(1 << ssid); - cgroup_refresh_subtree_ss_mask(scgrp); + scgrp->subtree_ss_mask = + cgroup_calc_subtree_ss_mask(scgrp->subtree_control, + cgroup_ss_mask(scgrp)); /* default hierarchy doesn't enable controllers by default */ dst_root->subsys_mask |= 1 << ssid; @@ -1600,7 +1585,9 @@ static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) static_branch_enable(cgroup_subsys_on_dfl_key[ssid]); } else { dcgrp->subtree_control |= 1 << ssid; - cgroup_refresh_subtree_ss_mask(dcgrp); + dcgrp->subtree_ss_mask = + cgroup_calc_subtree_ss_mask(dcgrp->subtree_control, + cgroup_ss_mask(dcgrp)); static_branch_disable(cgroup_subsys_on_dfl_key[ssid]); } @@ -3059,8 +3046,9 @@ 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)); } } @@ -5108,7 +5096,9 @@ static struct cgroup *cgroup_create(struct cgroup *parent) */ if (!cgroup_on_dfl(cgrp)) { cgrp->subtree_control = cgroup_control(cgrp); - cgroup_refresh_subtree_ss_mask(cgrp); + cgrp->subtree_ss_mask = + cgroup_calc_subtree_ss_mask(cgrp->subtree_control, + cgroup_ss_mask(cgrp)); } return cgrp; -- 2.5.0