From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 13 Feb 2015 15:52:24 +0100
Subject: cgroups: use simple wait in css_release()
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 4d35d49113b15581f9517adc6f96a7d0c4d23dc9
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
To avoid:
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:914
|in_atomic(): 1, irqs_disabled(): 0, pid: 92, name: rcuc/11
|2 locks held by rcuc/11/92:
| #0: (rcu_callback){......}, at: [<ffffffff810e037e>] rcu_cpu_kthread+0x3de/0x940
| #1: (rcu_read_lock_sched){......}, at: [<ffffffff81328390>] percpu_ref_call_confirm_rcu+0x0/0xd0
|Preemption disabled at:[<ffffffff813284e2>] percpu_ref_switch_to_atomic_rcu+0x82/0xc0
|CPU: 11 PID: 92 Comm: rcuc/11 Not tainted 3.18.7-rt0+ #1
| ffff8802398cdf80 ffff880235f0bc28 ffffffff815b3a12 0000000000000000
| 0000000000000000 ffff880235f0bc48 ffffffff8109aa16 0000000000000000
| ffff8802398cdf80 ffff880235f0bc78 ffffffff815b8dd4 000000000000df80
|Call Trace:
| [<ffffffff815b3a12>] dump_stack+0x4f/0x7c
| [<ffffffff8109aa16>] __might_sleep+0x116/0x190
| [<ffffffff815b8dd4>] rt_spin_lock+0x24/0x60
| [<ffffffff8108d2cd>] queue_work_on+0x6d/0x1d0
| [<ffffffff8110c881>] css_release+0x81/0x90
| [<ffffffff8132844e>] percpu_ref_call_confirm_rcu+0xbe/0xd0
| [<ffffffff813284e2>] percpu_ref_switch_to_atomic_rcu+0x82/0xc0
| [<ffffffff810e03e5>] rcu_cpu_kthread+0x445/0x940
| [<ffffffff81098a2d>] smpboot_thread_fn+0x18d/0x2d0
| [<ffffffff810948d8>] kthread+0xe8/0x100
| [<ffffffff815b9c3c>] ret_from_fork+0x7c/0xb0
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
include/linux/cgroup-defs.h | 2 ++
kernel/cgroup/cgroup.c | 9 +++++----
2 files changed, 7 insertions(+), 4 deletions(-)
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -18,6 +18,7 @@
#include <linux/percpu-rwsem.h>
#include <linux/workqueue.h>
#include <linux/bpf-cgroup.h>
+#include <linux/swork.h>
#ifdef CONFIG_CGROUPS
@@ -137,6 +138,7 @@ struct cgroup_subsys_state {
/* percpu_ref killing and RCU release */
struct rcu_head rcu_head;
struct work_struct destroy_work;
+ struct swork_event destroy_swork;
/*
* PI: the parent css. Placed here for cache proximity to following
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3899,10 +3899,10 @@ static void css_free_rcu_fn(struct rcu_h
queue_work(cgroup_destroy_wq, &css->destroy_work);
}
-static void css_release_work_fn(struct work_struct *work)
+static void css_release_work_fn(struct swork_event *sev)
{
struct cgroup_subsys_state *css =
- container_of(work, struct cgroup_subsys_state, destroy_work);
+ container_of(sev, struct cgroup_subsys_state, destroy_swork);
struct cgroup_subsys *ss = css->ss;
struct cgroup *cgrp = css->cgroup;
@@ -3947,8 +3947,8 @@ static void css_release(struct percpu_re
struct cgroup_subsys_state *css =
container_of(ref, struct cgroup_subsys_state, refcnt);
- INIT_WORK(&css->destroy_work, css_release_work_fn);
- queue_work(cgroup_destroy_wq, &css->destroy_work);
+ INIT_SWORK(&css->destroy_swork, css_release_work_fn);
+ swork_queue(&css->destroy_swork);
}
static void init_and_link_css(struct cgroup_subsys_state *css,
@@ -4609,6 +4609,7 @@ static int __init cgroup_wq_init(void)
*/
cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
BUG_ON(!cgroup_destroy_wq);
+ BUG_ON(swork_get());
return 0;
}
core_initcall(cgroup_wq_init);