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* [PATCH] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-04  2:53 ` Tahsin Erdogan
  0 siblings, 0 replies; 10+ messages in thread
From: Tahsin Erdogan @ 2017-03-04  2:53 UTC (permalink / raw)
  To: Johannes Weiner, Michal Hocko, Vladimir Davydov, cgroups
  Cc: linux-mm, linux-kernel, Tahsin Erdogan

mem_cgroup_free() indirectly calls wb_domain_exit() which is not
prepared to deal with a struct wb_domain object that hasn't executed
wb_domain_init(). For instance, the following warning message is
printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():

  INFO: trying to register non-static key.
  the code is fine but needs lockdep annotation.
  turning off the locking correctness validator.
  CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   register_lock_class+0x36d/0x540
   __lock_acquire+0x7f/0x1a30
   ? irq_work_queue+0x73/0x90
   ? wake_up_klogd+0x36/0x40
   ? console_unlock+0x45d/0x540
   ? vprintk_emit+0x211/0x2e0
   lock_acquire+0xcc/0x200
   ? try_to_del_timer_sync+0x60/0x60
   del_timer_sync+0x3c/0xc0
   ? try_to_del_timer_sync+0x60/0x60
   wb_domain_exit+0x14/0x20
   mem_cgroup_free+0x14/0x40
   mem_cgroup_css_alloc+0x3f9/0x620
   cgroup_apply_control_enable+0x190/0x390
   cgroup_mkdir+0x290/0x3d0
   kernfs_iop_mkdir+0x58/0x80
   vfs_mkdir+0x10e/0x1a0
   SyS_mkdirat+0xa8/0xd0
   SyS_mkdir+0x14/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad

Fix mem_cgroup_alloc() by doing more granular clean up in case of
failures.

Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
---
 mm/memcontrol.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c52ec893e241..9a9d5630df91 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4194,9 +4194,12 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 	idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
 	return memcg;
 fail:
+	for_each_node(node)
+		free_mem_cgroup_per_node_info(memcg, node);
+	free_percpu(memcg->stat);
 	if (memcg->id.id > 0)
 		idr_remove(&mem_cgroup_idr, memcg->id.id);
-	mem_cgroup_free(memcg);
+	kfree(memcg);
 	return NULL;
 }
 
-- 
2.12.0.rc1.440.g5b76565f74-goog

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-04  2:53 ` Tahsin Erdogan
  0 siblings, 0 replies; 10+ messages in thread
From: Tahsin Erdogan @ 2017-03-04  2:53 UTC (permalink / raw)
  To: Johannes Weiner, Michal Hocko, Vladimir Davydov, cgroups
  Cc: linux-mm, linux-kernel, Tahsin Erdogan

mem_cgroup_free() indirectly calls wb_domain_exit() which is not
prepared to deal with a struct wb_domain object that hasn't executed
wb_domain_init(). For instance, the following warning message is
printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():

  INFO: trying to register non-static key.
  the code is fine but needs lockdep annotation.
  turning off the locking correctness validator.
  CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   register_lock_class+0x36d/0x540
   __lock_acquire+0x7f/0x1a30
   ? irq_work_queue+0x73/0x90
   ? wake_up_klogd+0x36/0x40
   ? console_unlock+0x45d/0x540
   ? vprintk_emit+0x211/0x2e0
   lock_acquire+0xcc/0x200
   ? try_to_del_timer_sync+0x60/0x60
   del_timer_sync+0x3c/0xc0
   ? try_to_del_timer_sync+0x60/0x60
   wb_domain_exit+0x14/0x20
   mem_cgroup_free+0x14/0x40
   mem_cgroup_css_alloc+0x3f9/0x620
   cgroup_apply_control_enable+0x190/0x390
   cgroup_mkdir+0x290/0x3d0
   kernfs_iop_mkdir+0x58/0x80
   vfs_mkdir+0x10e/0x1a0
   SyS_mkdirat+0xa8/0xd0
   SyS_mkdir+0x14/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad

Fix mem_cgroup_alloc() by doing more granular clean up in case of
failures.

Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
---
 mm/memcontrol.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c52ec893e241..9a9d5630df91 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4194,9 +4194,12 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 	idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
 	return memcg;
 fail:
+	for_each_node(node)
+		free_mem_cgroup_per_node_info(memcg, node);
+	free_percpu(memcg->stat);
 	if (memcg->id.id > 0)
 		idr_remove(&mem_cgroup_idr, memcg->id.id);
-	mem_cgroup_free(memcg);
+	kfree(memcg);
 	return NULL;
 }
 
-- 
2.12.0.rc1.440.g5b76565f74-goog

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* Re: [PATCH] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
  2017-03-04  2:53 ` Tahsin Erdogan
@ 2017-03-06 13:59   ` Michal Hocko
  -1 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-06 13:59 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm, linux-kernel

On Fri 03-03-17 18:53:56, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Fix mem_cgroup_alloc() by doing more granular clean up in case of
> failures.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>

Please do not duplicate mem_cgroup_free code and rather add
__mem_cgroup_free which does everything except for wb_domain_exit.
An alternative would be to teach memcg_wb_domain_exit to not call
wb_domain_exit if it hasn't been initialized yet. The first option seems
easier.

Thanks!

> ---
>  mm/memcontrol.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..9a9d5630df91 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4194,9 +4194,12 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  	idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
>  	return memcg;
>  fail:
> +	for_each_node(node)
> +		free_mem_cgroup_per_node_info(memcg, node);
> +	free_percpu(memcg->stat);
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	kfree(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-06 13:59   ` Michal Hocko
  0 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-06 13:59 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm, linux-kernel

On Fri 03-03-17 18:53:56, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Fix mem_cgroup_alloc() by doing more granular clean up in case of
> failures.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>

Please do not duplicate mem_cgroup_free code and rather add
__mem_cgroup_free which does everything except for wb_domain_exit.
An alternative would be to teach memcg_wb_domain_exit to not call
wb_domain_exit if it hasn't been initialized yet. The first option seems
easier.

Thanks!

> ---
>  mm/memcontrol.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..9a9d5630df91 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4194,9 +4194,12 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  	idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
>  	return memcg;
>  fail:
> +	for_each_node(node)
> +		free_mem_cgroup_per_node_info(memcg, node);
> +	free_percpu(memcg->stat);
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	kfree(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

-- 
Michal Hocko
SUSE Labs

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
  2017-03-06 13:59   ` Michal Hocko
@ 2017-03-06 19:21     ` Tahsin Erdogan
  -1 siblings, 0 replies; 10+ messages in thread
From: Tahsin Erdogan @ 2017-03-06 19:21 UTC (permalink / raw)
  To: Johannes Weiner, Michal Hocko, Vladimir Davydov, cgroups
  Cc: linux-mm, linux-kernel, Tahsin Erdogan

mem_cgroup_free() indirectly calls wb_domain_exit() which is not
prepared to deal with a struct wb_domain object that hasn't executed
wb_domain_init(). For instance, the following warning message is
printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():

  INFO: trying to register non-static key.
  the code is fine but needs lockdep annotation.
  turning off the locking correctness validator.
  CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   register_lock_class+0x36d/0x540
   __lock_acquire+0x7f/0x1a30
   ? irq_work_queue+0x73/0x90
   ? wake_up_klogd+0x36/0x40
   ? console_unlock+0x45d/0x540
   ? vprintk_emit+0x211/0x2e0
   lock_acquire+0xcc/0x200
   ? try_to_del_timer_sync+0x60/0x60
   del_timer_sync+0x3c/0xc0
   ? try_to_del_timer_sync+0x60/0x60
   wb_domain_exit+0x14/0x20
   mem_cgroup_free+0x14/0x40
   mem_cgroup_css_alloc+0x3f9/0x620
   cgroup_apply_control_enable+0x190/0x390
   cgroup_mkdir+0x290/0x3d0
   kernfs_iop_mkdir+0x58/0x80
   vfs_mkdir+0x10e/0x1a0
   SyS_mkdirat+0xa8/0xd0
   SyS_mkdir+0x14/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad

Add __mem_cgroup_free() which skips wb_domain_exit(). This is
used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.

Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
---
v2:
  Added __mem_cgroup_free()

 mm/memcontrol.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c52ec893e241..e7d900c5f2d0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
 	kfree(memcg->nodeinfo[node]);
 }
 
-static void mem_cgroup_free(struct mem_cgroup *memcg)
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
 {
 	int node;
 
-	memcg_wb_domain_exit(memcg);
 	for_each_node(node)
 		free_mem_cgroup_per_node_info(memcg, node);
 	free_percpu(memcg->stat);
 	kfree(memcg);
 }
 
+static void mem_cgroup_free(struct mem_cgroup *memcg)
+{
+	memcg_wb_domain_exit(memcg);
+	__mem_cgroup_free(memcg);
+}
+
 static struct mem_cgroup *mem_cgroup_alloc(void)
 {
 	struct mem_cgroup *memcg;
@@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 fail:
 	if (memcg->id.id > 0)
 		idr_remove(&mem_cgroup_idr, memcg->id.id);
-	mem_cgroup_free(memcg);
+	__mem_cgroup_free(memcg);
 	return NULL;
 }
 
-- 
2.12.0.rc1.440.g5b76565f74-goog

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-06 19:21     ` Tahsin Erdogan
  0 siblings, 0 replies; 10+ messages in thread
From: Tahsin Erdogan @ 2017-03-06 19:21 UTC (permalink / raw)
  To: Johannes Weiner, Michal Hocko, Vladimir Davydov, cgroups
  Cc: linux-mm, linux-kernel, Tahsin Erdogan

mem_cgroup_free() indirectly calls wb_domain_exit() which is not
prepared to deal with a struct wb_domain object that hasn't executed
wb_domain_init(). For instance, the following warning message is
printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():

  INFO: trying to register non-static key.
  the code is fine but needs lockdep annotation.
  turning off the locking correctness validator.
  CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   register_lock_class+0x36d/0x540
   __lock_acquire+0x7f/0x1a30
   ? irq_work_queue+0x73/0x90
   ? wake_up_klogd+0x36/0x40
   ? console_unlock+0x45d/0x540
   ? vprintk_emit+0x211/0x2e0
   lock_acquire+0xcc/0x200
   ? try_to_del_timer_sync+0x60/0x60
   del_timer_sync+0x3c/0xc0
   ? try_to_del_timer_sync+0x60/0x60
   wb_domain_exit+0x14/0x20
   mem_cgroup_free+0x14/0x40
   mem_cgroup_css_alloc+0x3f9/0x620
   cgroup_apply_control_enable+0x190/0x390
   cgroup_mkdir+0x290/0x3d0
   kernfs_iop_mkdir+0x58/0x80
   vfs_mkdir+0x10e/0x1a0
   SyS_mkdirat+0xa8/0xd0
   SyS_mkdir+0x14/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad

Add __mem_cgroup_free() which skips wb_domain_exit(). This is
used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.

Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
---
v2:
  Added __mem_cgroup_free()

 mm/memcontrol.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c52ec893e241..e7d900c5f2d0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
 	kfree(memcg->nodeinfo[node]);
 }
 
-static void mem_cgroup_free(struct mem_cgroup *memcg)
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
 {
 	int node;
 
-	memcg_wb_domain_exit(memcg);
 	for_each_node(node)
 		free_mem_cgroup_per_node_info(memcg, node);
 	free_percpu(memcg->stat);
 	kfree(memcg);
 }
 
+static void mem_cgroup_free(struct mem_cgroup *memcg)
+{
+	memcg_wb_domain_exit(memcg);
+	__mem_cgroup_free(memcg);
+}
+
 static struct mem_cgroup *mem_cgroup_alloc(void)
 {
 	struct mem_cgroup *memcg;
@@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 fail:
 	if (memcg->id.id > 0)
 		idr_remove(&mem_cgroup_idr, memcg->id.id);
-	mem_cgroup_free(memcg);
+	__mem_cgroup_free(memcg);
 	return NULL;
 }
 
-- 
2.12.0.rc1.440.g5b76565f74-goog

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply related	[flat|nested] 10+ messages in thread

* Re: [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
  2017-03-06 19:21     ` Tahsin Erdogan
@ 2017-03-07  9:18       ` Michal Hocko
  -1 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-07  9:18 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm, linux-kernel

On Mon 06-03-17 11:21:22, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Add __mem_cgroup_free() which skips wb_domain_exit(). This is
> used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>

Acked-by: Michal Hocko <mhocko@suse.com>

Thanks!

> ---
> v2:
>   Added __mem_cgroup_free()
> 
>  mm/memcontrol.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..e7d900c5f2d0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
>  	kfree(memcg->nodeinfo[node]);
>  }
>  
> -static void mem_cgroup_free(struct mem_cgroup *memcg)
> +static void __mem_cgroup_free(struct mem_cgroup *memcg)
>  {
>  	int node;
>  
> -	memcg_wb_domain_exit(memcg);
>  	for_each_node(node)
>  		free_mem_cgroup_per_node_info(memcg, node);
>  	free_percpu(memcg->stat);
>  	kfree(memcg);
>  }
>  
> +static void mem_cgroup_free(struct mem_cgroup *memcg)
> +{
> +	memcg_wb_domain_exit(memcg);
> +	__mem_cgroup_free(memcg);
> +}
> +
>  static struct mem_cgroup *mem_cgroup_alloc(void)
>  {
>  	struct mem_cgroup *memcg;
> @@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  fail:
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	__mem_cgroup_free(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-07  9:18       ` Michal Hocko
  0 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-07  9:18 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm, linux-kernel

On Mon 06-03-17 11:21:22, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Add __mem_cgroup_free() which skips wb_domain_exit(). This is
> used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>

Acked-by: Michal Hocko <mhocko@suse.com>

Thanks!

> ---
> v2:
>   Added __mem_cgroup_free()
> 
>  mm/memcontrol.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..e7d900c5f2d0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
>  	kfree(memcg->nodeinfo[node]);
>  }
>  
> -static void mem_cgroup_free(struct mem_cgroup *memcg)
> +static void __mem_cgroup_free(struct mem_cgroup *memcg)
>  {
>  	int node;
>  
> -	memcg_wb_domain_exit(memcg);
>  	for_each_node(node)
>  		free_mem_cgroup_per_node_info(memcg, node);
>  	free_percpu(memcg->stat);
>  	kfree(memcg);
>  }
>  
> +static void mem_cgroup_free(struct mem_cgroup *memcg)
> +{
> +	memcg_wb_domain_exit(memcg);
> +	__mem_cgroup_free(memcg);
> +}
> +
>  static struct mem_cgroup *mem_cgroup_alloc(void)
>  {
>  	struct mem_cgroup *memcg;
> @@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  fail:
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	__mem_cgroup_free(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog

-- 
Michal Hocko
SUSE Labs

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
  2017-03-06 19:21     ` Tahsin Erdogan
@ 2017-03-07 11:40       ` Michal Hocko
  -1 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-07 11:40 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm,
	linux-kernel, Andrew Morton

[CC Andrew]

On Mon 06-03-17 11:21:22, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Add __mem_cgroup_free() which skips wb_domain_exit(). This is
> used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>
> ---
> v2:
>   Added __mem_cgroup_free()
> 
>  mm/memcontrol.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..e7d900c5f2d0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
>  	kfree(memcg->nodeinfo[node]);
>  }
>  
> -static void mem_cgroup_free(struct mem_cgroup *memcg)
> +static void __mem_cgroup_free(struct mem_cgroup *memcg)
>  {
>  	int node;
>  
> -	memcg_wb_domain_exit(memcg);
>  	for_each_node(node)
>  		free_mem_cgroup_per_node_info(memcg, node);
>  	free_percpu(memcg->stat);
>  	kfree(memcg);
>  }
>  
> +static void mem_cgroup_free(struct mem_cgroup *memcg)
> +{
> +	memcg_wb_domain_exit(memcg);
> +	__mem_cgroup_free(memcg);
> +}
> +
>  static struct mem_cgroup *mem_cgroup_alloc(void)
>  {
>  	struct mem_cgroup *memcg;
> @@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  fail:
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	__mem_cgroup_free(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog

-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
@ 2017-03-07 11:40       ` Michal Hocko
  0 siblings, 0 replies; 10+ messages in thread
From: Michal Hocko @ 2017-03-07 11:40 UTC (permalink / raw)
  To: Tahsin Erdogan
  Cc: Johannes Weiner, Vladimir Davydov, cgroups, linux-mm,
	linux-kernel, Andrew Morton

[CC Andrew]

On Mon 06-03-17 11:21:22, Tahsin Erdogan wrote:
> mem_cgroup_free() indirectly calls wb_domain_exit() which is not
> prepared to deal with a struct wb_domain object that hasn't executed
> wb_domain_init(). For instance, the following warning message is
> printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc():
> 
>   INFO: trying to register non-static key.
>   the code is fine but needs lockdep annotation.
>   turning off the locking correctness validator.
>   CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151
>   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>   Call Trace:
>    dump_stack+0x67/0x99
>    register_lock_class+0x36d/0x540
>    __lock_acquire+0x7f/0x1a30
>    ? irq_work_queue+0x73/0x90
>    ? wake_up_klogd+0x36/0x40
>    ? console_unlock+0x45d/0x540
>    ? vprintk_emit+0x211/0x2e0
>    lock_acquire+0xcc/0x200
>    ? try_to_del_timer_sync+0x60/0x60
>    del_timer_sync+0x3c/0xc0
>    ? try_to_del_timer_sync+0x60/0x60
>    wb_domain_exit+0x14/0x20
>    mem_cgroup_free+0x14/0x40
>    mem_cgroup_css_alloc+0x3f9/0x620
>    cgroup_apply_control_enable+0x190/0x390
>    cgroup_mkdir+0x290/0x3d0
>    kernfs_iop_mkdir+0x58/0x80
>    vfs_mkdir+0x10e/0x1a0
>    SyS_mkdirat+0xa8/0xd0
>    SyS_mkdir+0x14/0x20
>    entry_SYSCALL_64_fastpath+0x18/0xad
> 
> Add __mem_cgroup_free() which skips wb_domain_exit(). This is
> used by both mem_cgroup_free() and mem_cgroup_alloc() clean up.
> 
> Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions")
> Signed-off-by: Tahsin Erdogan <tahsin@google.com>
> ---
> v2:
>   Added __mem_cgroup_free()
> 
>  mm/memcontrol.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index c52ec893e241..e7d900c5f2d0 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4135,17 +4135,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
>  	kfree(memcg->nodeinfo[node]);
>  }
>  
> -static void mem_cgroup_free(struct mem_cgroup *memcg)
> +static void __mem_cgroup_free(struct mem_cgroup *memcg)
>  {
>  	int node;
>  
> -	memcg_wb_domain_exit(memcg);
>  	for_each_node(node)
>  		free_mem_cgroup_per_node_info(memcg, node);
>  	free_percpu(memcg->stat);
>  	kfree(memcg);
>  }
>  
> +static void mem_cgroup_free(struct mem_cgroup *memcg)
> +{
> +	memcg_wb_domain_exit(memcg);
> +	__mem_cgroup_free(memcg);
> +}
> +
>  static struct mem_cgroup *mem_cgroup_alloc(void)
>  {
>  	struct mem_cgroup *memcg;
> @@ -4196,7 +4201,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>  fail:
>  	if (memcg->id.id > 0)
>  		idr_remove(&mem_cgroup_idr, memcg->id.id);
> -	mem_cgroup_free(memcg);
> +	__mem_cgroup_free(memcg);
>  	return NULL;
>  }
>  
> -- 
> 2.12.0.rc1.440.g5b76565f74-goog

-- 
Michal Hocko
SUSE Labs

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2017-03-07 11:56 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-03-04  2:53 [PATCH] mm: do not call mem_cgroup_free() from within mem_cgroup_alloc() Tahsin Erdogan
2017-03-04  2:53 ` Tahsin Erdogan
2017-03-06 13:59 ` Michal Hocko
2017-03-06 13:59   ` Michal Hocko
2017-03-06 19:21   ` [PATCH v2] " Tahsin Erdogan
2017-03-06 19:21     ` Tahsin Erdogan
2017-03-07  9:18     ` Michal Hocko
2017-03-07  9:18       ` Michal Hocko
2017-03-07 11:40     ` Michal Hocko
2017-03-07 11:40       ` Michal Hocko

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