* [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit()
@ 2014-03-28 7:18 ` Li Zefan
0 siblings, 0 replies; 6+ messages in thread
From: Li Zefan @ 2014-03-28 7:18 UTC (permalink / raw)
To: Tejun Heo; +Cc: Sasha Levin, LKML, Cgroups
cgroup_exit() is called in fork and exit path. If it's called in the
failure path during fork, PF_EXITING isn't set, and then lockdep will
complain.
Fix this by removing cgroup_exit() in that failure path. cgroup_fork()
does nothing that needs cleanup.
Reported-by: Sasha Levin <sasha.levin-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
---
kernel/cgroup.c | 3 +--
kernel/fork.c | 5 ++---
2 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8f4ddbe..a53dbc6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4339,8 +4339,7 @@ void cgroup_post_fork(struct task_struct *child)
* notify_on_release(), then leave the task attached to the root cgroup in
* each hierarchy for the remainder of its exit. No need to bother with
* init_css_set refcnting. init_css_set never goes away and we can't race
- * with migration path - either PF_EXITING is visible to migration path or
- * @tsk never got on the tasklist.
+ * with migration path - PF_EXITING is visible to migration path.
*/
void cgroup_exit(struct task_struct *tsk, int run_callbacks)
{
diff --git a/kernel/fork.c b/kernel/fork.c
index 3e02737..0477657 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1274,7 +1274,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (IS_ERR(p->mempolicy)) {
retval = PTR_ERR(p->mempolicy);
p->mempolicy = NULL;
- goto bad_fork_cleanup_cgroup;
+ goto bad_fork_cleanup_threadgroup_lock;
}
#endif
#ifdef CONFIG_CPUSETS
@@ -1526,11 +1526,10 @@ bad_fork_cleanup_policy:
perf_event_free_task(p);
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
-bad_fork_cleanup_cgroup:
+bad_fork_cleanup_threadgroup_lock:
#endif
if (clone_flags & CLONE_THREAD)
threadgroup_change_end(current);
- cgroup_exit(p, 0);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
--
1.8.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit()
@ 2014-03-28 7:18 ` Li Zefan
0 siblings, 0 replies; 6+ messages in thread
From: Li Zefan @ 2014-03-28 7:18 UTC (permalink / raw)
To: Tejun Heo; +Cc: Sasha Levin, LKML, Cgroups
cgroup_exit() is called in fork and exit path. If it's called in the
failure path during fork, PF_EXITING isn't set, and then lockdep will
complain.
Fix this by removing cgroup_exit() in that failure path. cgroup_fork()
does nothing that needs cleanup.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
---
kernel/cgroup.c | 3 +--
kernel/fork.c | 5 ++---
2 files changed, 3 insertions(+), 5 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8f4ddbe..a53dbc6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4339,8 +4339,7 @@ void cgroup_post_fork(struct task_struct *child)
* notify_on_release(), then leave the task attached to the root cgroup in
* each hierarchy for the remainder of its exit. No need to bother with
* init_css_set refcnting. init_css_set never goes away and we can't race
- * with migration path - either PF_EXITING is visible to migration path or
- * @tsk never got on the tasklist.
+ * with migration path - PF_EXITING is visible to migration path.
*/
void cgroup_exit(struct task_struct *tsk, int run_callbacks)
{
diff --git a/kernel/fork.c b/kernel/fork.c
index 3e02737..0477657 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1274,7 +1274,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (IS_ERR(p->mempolicy)) {
retval = PTR_ERR(p->mempolicy);
p->mempolicy = NULL;
- goto bad_fork_cleanup_cgroup;
+ goto bad_fork_cleanup_threadgroup_lock;
}
#endif
#ifdef CONFIG_CPUSETS
@@ -1526,11 +1526,10 @@ bad_fork_cleanup_policy:
perf_event_free_task(p);
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
-bad_fork_cleanup_cgroup:
+bad_fork_cleanup_threadgroup_lock:
#endif
if (clone_flags & CLONE_THREAD)
threadgroup_change_end(current);
- cgroup_exit(p, 0);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
--
1.8.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread[parent not found: <53352243.80805-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>]
* [PATCH 2/2] cgroup: remove useless argument from cgroup_exit()
2014-03-28 7:18 ` Li Zefan
@ 2014-03-28 7:22 ` Li Zefan
-1 siblings, 0 replies; 6+ messages in thread
From: Li Zefan @ 2014-03-28 7:22 UTC (permalink / raw)
To: Tejun Heo; +Cc: Sasha Levin, LKML, Cgroups
Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
---
include/linux/cgroup.h | 4 ++--
kernel/cgroup.c | 5 ++---
kernel/exit.c | 2 +-
3 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index acbb9a4..13ffb06 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -33,7 +33,7 @@ extern int cgroup_init_early(void);
extern int cgroup_init(void);
extern void cgroup_fork(struct task_struct *p);
extern void cgroup_post_fork(struct task_struct *p);
-extern void cgroup_exit(struct task_struct *p, int run_callbacks);
+extern void cgroup_exit(struct task_struct *p);
extern int cgroupstats_build(struct cgroupstats *stats,
struct dentry *dentry);
@@ -848,7 +848,7 @@ static inline int cgroup_init_early(void) { return 0; }
static inline int cgroup_init(void) { return 0; }
static inline void cgroup_fork(struct task_struct *p) {}
static inline void cgroup_post_fork(struct task_struct *p) {}
-static inline void cgroup_exit(struct task_struct *p, int callbacks) {}
+static inline void cgroup_exit(struct task_struct *p) {}
static inline int cgroupstats_build(struct cgroupstats *stats,
struct dentry *dentry)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a53dbc6..775a90d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4324,7 +4324,6 @@ void cgroup_post_fork(struct task_struct *child)
/**
* cgroup_exit - detach cgroup from exiting task
* @tsk: pointer to task_struct of exiting process
- * @run_callback: run exit callbacks?
*
* Description: Detach cgroup from @tsk and release it.
*
@@ -4341,7 +4340,7 @@ void cgroup_post_fork(struct task_struct *child)
* init_css_set refcnting. init_css_set never goes away and we can't race
* with migration path - PF_EXITING is visible to migration path.
*/
-void cgroup_exit(struct task_struct *tsk, int run_callbacks)
+void cgroup_exit(struct task_struct *tsk)
{
struct cgroup_subsys *ss;
struct css_set *cset;
@@ -4363,7 +4362,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
cset = task_css_set(tsk);
RCU_INIT_POINTER(tsk->cgroups, &init_css_set);
- if (run_callbacks && need_forkexit_callback) {
+ if (need_forkexit_callback) {
/* see cgroup_post_fork() for details */
for_each_subsys(ss, i) {
if (ss->exit) {
diff --git a/kernel/exit.c b/kernel/exit.c
index c3af836..c2ae892 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -797,7 +797,7 @@ void do_exit(long code)
*/
perf_event_exit_task(tsk);
- cgroup_exit(tsk, 1);
+ cgroup_exit(tsk);
if (group_dead)
disassociate_ctty(1);
--
1.8.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/2] cgroup: remove useless argument from cgroup_exit()
@ 2014-03-28 7:22 ` Li Zefan
0 siblings, 0 replies; 6+ messages in thread
From: Li Zefan @ 2014-03-28 7:22 UTC (permalink / raw)
To: Tejun Heo; +Cc: Sasha Levin, LKML, Cgroups
Signed-off-by: Li Zefan <lizefan@huawei.com>
---
include/linux/cgroup.h | 4 ++--
kernel/cgroup.c | 5 ++---
kernel/exit.c | 2 +-
3 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index acbb9a4..13ffb06 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -33,7 +33,7 @@ extern int cgroup_init_early(void);
extern int cgroup_init(void);
extern void cgroup_fork(struct task_struct *p);
extern void cgroup_post_fork(struct task_struct *p);
-extern void cgroup_exit(struct task_struct *p, int run_callbacks);
+extern void cgroup_exit(struct task_struct *p);
extern int cgroupstats_build(struct cgroupstats *stats,
struct dentry *dentry);
@@ -848,7 +848,7 @@ static inline int cgroup_init_early(void) { return 0; }
static inline int cgroup_init(void) { return 0; }
static inline void cgroup_fork(struct task_struct *p) {}
static inline void cgroup_post_fork(struct task_struct *p) {}
-static inline void cgroup_exit(struct task_struct *p, int callbacks) {}
+static inline void cgroup_exit(struct task_struct *p) {}
static inline int cgroupstats_build(struct cgroupstats *stats,
struct dentry *dentry)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a53dbc6..775a90d 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4324,7 +4324,6 @@ void cgroup_post_fork(struct task_struct *child)
/**
* cgroup_exit - detach cgroup from exiting task
* @tsk: pointer to task_struct of exiting process
- * @run_callback: run exit callbacks?
*
* Description: Detach cgroup from @tsk and release it.
*
@@ -4341,7 +4340,7 @@ void cgroup_post_fork(struct task_struct *child)
* init_css_set refcnting. init_css_set never goes away and we can't race
* with migration path - PF_EXITING is visible to migration path.
*/
-void cgroup_exit(struct task_struct *tsk, int run_callbacks)
+void cgroup_exit(struct task_struct *tsk)
{
struct cgroup_subsys *ss;
struct css_set *cset;
@@ -4363,7 +4362,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
cset = task_css_set(tsk);
RCU_INIT_POINTER(tsk->cgroups, &init_css_set);
- if (run_callbacks && need_forkexit_callback) {
+ if (need_forkexit_callback) {
/* see cgroup_post_fork() for details */
for_each_subsys(ss, i) {
if (ss->exit) {
diff --git a/kernel/exit.c b/kernel/exit.c
index c3af836..c2ae892 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -797,7 +797,7 @@ void do_exit(long code)
*/
perf_event_exit_task(tsk);
- cgroup_exit(tsk, 1);
+ cgroup_exit(tsk);
if (group_dead)
disassociate_ctty(1);
--
1.8.0.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit()
2014-03-28 7:18 ` Li Zefan
@ 2014-03-29 13:18 ` Tejun Heo
-1 siblings, 0 replies; 6+ messages in thread
From: Tejun Heo @ 2014-03-29 13:18 UTC (permalink / raw)
To: Li Zefan; +Cc: Sasha Levin, LKML, Cgroups
On Fri, Mar 28, 2014 at 03:18:27PM +0800, Li Zefan wrote:
> cgroup_exit() is called in fork and exit path. If it's called in the
> failure path during fork, PF_EXITING isn't set, and then lockdep will
> complain.
>
> Fix this by removing cgroup_exit() in that failure path. cgroup_fork()
> does nothing that needs cleanup.
>
> Reported-by: Sasha Levin <sasha.levin-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Applied 1-2 to cgroup/for-3.15.
Thanks!
--
tejun
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit()
@ 2014-03-29 13:18 ` Tejun Heo
0 siblings, 0 replies; 6+ messages in thread
From: Tejun Heo @ 2014-03-29 13:18 UTC (permalink / raw)
To: Li Zefan; +Cc: Sasha Levin, LKML, Cgroups
On Fri, Mar 28, 2014 at 03:18:27PM +0800, Li Zefan wrote:
> cgroup_exit() is called in fork and exit path. If it's called in the
> failure path during fork, PF_EXITING isn't set, and then lockdep will
> complain.
>
> Fix this by removing cgroup_exit() in that failure path. cgroup_fork()
> does nothing that needs cleanup.
>
> Reported-by: Sasha Levin <sasha.levin@oracle.com>
> Signed-off-by: Li Zefan <lizefan@huawei.com>
Applied 1-2 to cgroup/for-3.15.
Thanks!
--
tejun
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-03-29 13:18 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2014-03-28 7:18 [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit() Li Zefan
2014-03-28 7:18 ` Li Zefan
[not found] ` <53352243.80805-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-03-28 7:22 ` [PATCH 2/2] cgroup: remove useless argument from cgroup_exit() Li Zefan
2014-03-28 7:22 ` Li Zefan
2014-03-29 13:18 ` [PATCH 1/2] cgroup: fix spurious lockdep warning in cgroup_exit() Tejun Heo
2014-03-29 13:18 ` Tejun Heo
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