From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754864Ab2KCIjd (ORCPT ); Sat, 3 Nov 2012 04:39:33 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:33714 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754694Ab2KCIj1 (ORCPT ); Sat, 3 Nov 2012 04:39:27 -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 7/9] cgroup_freezer: introduce CGROUP_FREEZING_[SELF|PARENT] Date: Sat, 3 Nov 2012 01:38:33 -0700 Message-Id: <1351931915-1701-8-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 Introduce FREEZING_SELF and FREEZING_PARENT and make FREEZING OR of the two flags. This is to prepare for full hierarchy support. freezer_apply_date() is updated such that it can handle setting and clearing of both flags. The two flags are also exposed to userland via read-only files self_freezing and parent_freezing. Other than the added cgroupfs files, this patch doesn't introduce any behavior change. Signed-off-by: Tejun Heo --- kernel/cgroup_freezer.c | 55 ++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 47 insertions(+), 8 deletions(-) diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index e76aa9f..b8ad93c 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -23,8 +23,12 @@ #include enum freezer_state_flags { - CGROUP_FREEZING = (1 << 1), /* this freezer is freezing */ + CGROUP_FREEZING_SELF = (1 << 1), /* this freezer is freezing */ + CGROUP_FREEZING_PARENT = (1 << 2), /* the parent freezer is freezing */ CGROUP_FROZEN = (1 << 3), /* this and its descendants frozen */ + + /* mask for all FREEZING flags */ + CGROUP_FREEZING = CGROUP_FREEZING_SELF | CGROUP_FREEZING_PARENT, }; struct freezer { @@ -245,8 +249,13 @@ static void unfreeze_cgroup(struct freezer *freezer) * freezer_apply_state - apply state change to a single cgroup_freezer * @freezer: freezer to apply state change to * @freeze: whether to freeze or unfreeze + * @state: CGROUP_FREEZING_* flag to set or clear + * + * Set or clear @state on @cgroup according to @freeze, and perform + * freezing or thawing as necessary. */ -static void freezer_apply_state(struct freezer *freezer, bool freeze) +static void freezer_apply_state(struct freezer *freezer, bool freeze, + unsigned int state) { /* also synchronizes against task migration, see freezer_attach() */ lockdep_assert_held(&freezer->lock); @@ -254,13 +263,19 @@ static void freezer_apply_state(struct freezer *freezer, bool freeze) if (freeze) { if (!(freezer->state & CGROUP_FREEZING)) atomic_inc(&system_freezing_cnt); - freezer->state |= CGROUP_FREEZING; + freezer->state |= state; freeze_cgroup(freezer); } else { - if (freezer->state & CGROUP_FREEZING) - atomic_dec(&system_freezing_cnt); - freezer->state &= ~(CGROUP_FREEZING | CGROUP_FROZEN); - unfreeze_cgroup(freezer); + bool was_freezing = freezer->state & CGROUP_FREEZING; + + freezer->state &= ~state; + + if (!(freezer->state & CGROUP_FREEZING)) { + if (was_freezing) + atomic_dec(&system_freezing_cnt); + freezer->state &= ~CGROUP_FROZEN; + unfreeze_cgroup(freezer); + } } } @@ -275,7 +290,7 @@ static void freezer_change_state(struct freezer *freezer, bool freeze) { /* update @freezer */ spin_lock_irq(&freezer->lock); - freezer_apply_state(freezer, freeze); + freezer_apply_state(freezer, freeze, CGROUP_FREEZING_SELF); spin_unlock_irq(&freezer->lock); } @@ -295,6 +310,20 @@ static int freezer_write(struct cgroup *cgroup, struct cftype *cft, return 0; } +static u64 freezer_self_freezing_read(struct cgroup *cgroup, struct cftype *cft) +{ + struct freezer *freezer = cgroup_freezer(cgroup); + + return (bool)(freezer->state & CGROUP_FREEZING_SELF); +} + +static u64 freezer_parent_freezing_read(struct cgroup *cgroup, struct cftype *cft) +{ + struct freezer *freezer = cgroup_freezer(cgroup); + + return (bool)(freezer->state & CGROUP_FREEZING_PARENT); +} + static struct cftype files[] = { { .name = "state", @@ -302,6 +331,16 @@ static struct cftype files[] = { .read_seq_string = freezer_read, .write_string = freezer_write, }, + { + .name = "self_freezing", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = freezer_self_freezing_read, + }, + { + .name = "parent_freezing", + .flags = CFTYPE_NOT_ON_ROOT, + .read_u64 = freezer_parent_freezing_read, + }, { } /* terminate */ }; -- 1.7.11.7