locking, sched, cgroups: Annotate release_list_lock as raw

The release_list_lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1d2b6ceea95d9d268191a76fd486e7958cc2d05c..453100a4159d3eed6b82307f7fed09f12eec1937 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -265,7 +265,7 @@ list_for_each_entry(_root, &roots, root_list)
 /* the list of cgroups eligible for automatic release. Protected by
  * release_list_lock */
 static LIST_HEAD(release_list);
-static DEFINE_SPINLOCK(release_list_lock);
+static DEFINE_RAW_SPINLOCK(release_list_lock);
 static void cgroup_release_agent(struct work_struct *work);
 static DECLARE_WORK(release_agent_work, cgroup_release_agent);
 static void check_for_release(struct cgroup *cgrp);
@@ -4014,11 +4014,11 @@ again:
        finish_wait(&cgroup_rmdir_waitq, &wait);
        clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags);
 
-       spin_lock(&release_list_lock);
+       raw_spin_lock(&release_list_lock);
        set_bit(CGRP_REMOVED, &cgrp->flags);
        if (!list_empty(&cgrp->release_list))
                list_del_init(&cgrp->release_list);
-       spin_unlock(&release_list_lock);
+       raw_spin_unlock(&release_list_lock);
 
        cgroup_lock_hierarchy(cgrp->root);
        /* delete this cgroup from parent->children */
@@ -4671,13 +4671,13 @@ static void check_for_release(struct cgroup *cgrp)
                 * already queued for a userspace notification, queue
                 * it now */
                int need_schedule_work = 0;
-               spin_lock(&release_list_lock);
+               raw_spin_lock(&release_list_lock);
                if (!cgroup_is_removed(cgrp) &&
                    list_empty(&cgrp->release_list)) {
                        list_add(&cgrp->release_list, &release_list);
                        need_schedule_work = 1;
                }
-               spin_unlock(&release_list_lock);
+               raw_spin_unlock(&release_list_lock);
                if (need_schedule_work)
                        schedule_work(&release_agent_work);
        }
@@ -4729,7 +4729,7 @@ static void cgroup_release_agent(struct work_struct *work)
 {
        BUG_ON(work != &release_agent_work);
        mutex_lock(&cgroup_mutex);
-       spin_lock(&release_list_lock);
+       raw_spin_lock(&release_list_lock);
        while (!list_empty(&release_list)) {
                char *argv[3], *envp[3];
                int i;
@@ -4738,7 +4738,7 @@ static void cgroup_release_agent(struct work_struct *work)
                                                    struct cgroup,
                                                    release_list);
                list_del_init(&cgrp->release_list);
-               spin_unlock(&release_list_lock);
+               raw_spin_unlock(&release_list_lock);
                pathbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
                if (!pathbuf)
                        goto continue_free;
@@ -4768,9 +4768,9 @@ static void cgroup_release_agent(struct work_struct *work)
  continue_free:
                kfree(pathbuf);
                kfree(agentbuf);
-               spin_lock(&release_list_lock);
+               raw_spin_lock(&release_list_lock);
        }
-       spin_unlock(&release_list_lock);
+       raw_spin_unlock(&release_list_lock);
        mutex_unlock(&cgroup_mutex);
 }