diff options
author | Colin Cross <ccross@android.com> | 2010-11-23 21:37:03 -0800 |
---|---|---|
committer | Colin Cross <ccross@android.com> | 2012-04-09 13:53:11 -0700 |
commit | c0f6fa8c409fc7fe63bfd0a57efad29dec262bcb (patch) | |
tree | 55038e534a392da0691a5d88102cdb3110215696 /kernel/cgroup.c | |
parent | e5e483d13369ab62d95f1738edce3cd64c7ca2ff (diff) |
cgroup: Set CGRP_RELEASABLE when adding to a cgroup
Changes the meaning of CGRP_RELEASABLE to be set on any cgroup
that has ever had a task or cgroup in it, or had css_get called
on it. The bit is set in cgroup_attach_task, cgroup_create,
and __css_get. It is not necessary to set the bit in
cgroup_fork, as the task is either in the root cgroup, in
which can never be released, or the task it was forked from
already set the bit in croup_attach_task.
Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r-- | kernel/cgroup.c | 53 |
1 files changed, 23 insertions, 30 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ed64ccac67c..0de816098bf 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -352,7 +352,15 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) * compiled into their kernel but not actually in use */ static int use_task_css_set_links __read_mostly; -static void __put_css_set(struct css_set *cg, int taskexit) +/* + * refcounted get/put for css_set objects + */ +static inline void get_css_set(struct css_set *cg) +{ + atomic_inc(&cg->refcount); +} + +static void put_css_set(struct css_set *cg) { struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; @@ -378,12 +386,8 @@ static void __put_css_set(struct css_set *cg, int taskexit) struct cgroup *cgrp = link->cgrp; list_del(&link->cg_link_list); list_del(&link->cgrp_link_list); - if (atomic_dec_and_test(&cgrp->count) && - notify_on_release(cgrp)) { - if (taskexit) - set_bit(CGRP_RELEASABLE, &cgrp->flags); + if (atomic_dec_and_test(&cgrp->count)) check_for_release(cgrp); - } kfree(link); } @@ -393,24 +397,6 @@ static void __put_css_set(struct css_set *cg, int taskexit) } /* - * refcounted get/put for css_set objects - */ -static inline void get_css_set(struct css_set *cg) -{ - atomic_inc(&cg->refcount); -} - -static inline void put_css_set(struct css_set *cg) -{ - __put_css_set(cg, 0); -} - -static inline void put_css_set_taskexit(struct css_set *cg) -{ - __put_css_set(cg, 1); -} - -/* * compare_css_sets - helper function for find_existing_css_set(). * @cg: candidate css_set being tested * @old_cg: existing css_set for a task @@ -1931,6 +1917,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) ss->attach(cgrp, &tset); } + set_bit(CGRP_RELEASABLE, &cgrp->flags); synchronize_rcu(); /* @@ -3784,6 +3771,8 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, if (err < 0) goto err_remove; + set_bit(CGRP_RELEASABLE, &parent->flags); + /* The cgroup directory was pre-locked for us */ BUG_ON(!mutex_is_locked(&cgrp->dentry->d_inode->i_mutex)); @@ -4000,7 +3989,6 @@ again: cgroup_d_remove_dir(d); dput(d); - set_bit(CGRP_RELEASABLE, &parent->flags); check_for_release(parent); /* @@ -4631,7 +4619,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) task_unlock(tsk); if (cg) - put_css_set_taskexit(cg); + put_css_set(cg); } /** @@ -4685,6 +4673,14 @@ static void check_for_release(struct cgroup *cgrp) } /* Caller must verify that the css is not for root cgroup */ +void __css_get(struct cgroup_subsys_state *css, int count) +{ + atomic_add(count, &css->refcnt); + set_bit(CGRP_RELEASABLE, &css->cgroup->flags); +} +EXPORT_SYMBOL_GPL(__css_get); + +/* Caller must verify that the css is not for root cgroup */ void __css_put(struct cgroup_subsys_state *css, int count) { struct cgroup *cgrp = css->cgroup; @@ -4692,10 +4688,7 @@ void __css_put(struct cgroup_subsys_state *css, int count) rcu_read_lock(); val = atomic_sub_return(count, &css->refcnt); if (val == 1) { - if (notify_on_release(cgrp)) { - set_bit(CGRP_RELEASABLE, &cgrp->flags); - check_for_release(cgrp); - } + check_for_release(cgrp); cgroup_wakeup_rmdir_waiter(cgrp); } rcu_read_unlock(); |