From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754702Ab2KCIj0 (ORCPT ); Sat, 3 Nov 2012 04:39:26 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:36901 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753745Ab2KCIjS (ORCPT ); Sat, 3 Nov 2012 04:39:18 -0400 From: Tejun Heo To: lizefan@huawei.com, mhocko@suse.cz, rjw@sisk.pl Cc: containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, fweisbec@gmail.com, Tejun Heo Subject: [PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support Date: Sat, 3 Nov 2012 01:38:31 -0700 Message-Id: <1351931915-1701-6-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1351931915-1701-1-git-send-email-tj@kernel.org> References: <1351931915-1701-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Make freezer_change_state() take bool @freeze instead of enum freezer_state. * Separate out freezer_apply_state() out of freezer_change_state(). This makes freezer_change_state() a rather silly thin wrapper. It will be filled with hierarchy handling later on. This patch doesn't introduce any behavior change. Signed-off-by: Tejun Heo --- kernel/cgroup_freezer.c | 48 ++++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 975b3d8..2690830 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -247,45 +247,57 @@ static void unfreeze_cgroup(struct freezer *freezer) cgroup_iter_end(cgroup, &it); } -static void freezer_change_state(struct freezer *freezer, - enum freezer_state goal_state) +/** + * freezer_apply_state - apply state change to a single cgroup_freezer + * @freezer: freezer to apply state change to + * @freeze: whether to freeze or unfreeze + */ +static void freezer_apply_state(struct freezer *freezer, bool freeze) { /* also synchronizes against task migration, see freezer_attach() */ - spin_lock_irq(&freezer->lock); + lockdep_assert_held(&freezer->lock); - switch (goal_state) { - case CGROUP_THAWED: - if (freezer->state != CGROUP_THAWED) - atomic_dec(&system_freezing_cnt); - freezer->state = CGROUP_THAWED; - unfreeze_cgroup(freezer); - break; - case CGROUP_FROZEN: + if (freeze) { if (freezer->state == CGROUP_THAWED) atomic_inc(&system_freezing_cnt); freezer->state = CGROUP_FREEZING; freeze_cgroup(freezer); - break; - default: - BUG(); + } else { + if (freezer->state != CGROUP_THAWED) + atomic_dec(&system_freezing_cnt); + freezer->state = CGROUP_THAWED; + unfreeze_cgroup(freezer); } +} +/** + * freezer_change_state - change the freezing state of a cgroup_freezer + * @freezer: freezer of interest + * @freeze: whether to freeze or thaw + * + * Freeze or thaw @cgroup according to @freeze. + */ +static void freezer_change_state(struct freezer *freezer, bool freeze) +{ + /* update @freezer */ + spin_lock_irq(&freezer->lock); + freezer_apply_state(freezer, freeze); spin_unlock_irq(&freezer->lock); } static int freezer_write(struct cgroup *cgroup, struct cftype *cft, const char *buffer) { - enum freezer_state goal_state; + bool freeze; if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0) - goal_state = CGROUP_THAWED; + freeze = false; else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0) - goal_state = CGROUP_FROZEN; + freeze = true; else return -EINVAL; - freezer_change_state(cgroup_freezer(cgroup), goal_state); + freezer_change_state(cgroup_freezer(cgroup), freeze); return 0; } -- 1.7.11.7