Re: [PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-08 Thread Michal Hocko 
On Sat 03-11-12 01:38:31, Tejun Heo wrote:
> * Make freezer_change_state() take bool @freeze instead of enum
>   freezer_state.
> 
> * Separate out freezer_apply_state() out of freezer_change_state().
>   This makes freezer_change_state() a rather silly thin wrapper.  It
>   will be filled with hierarchy handling later on.
> 
> This patch doesn't introduce any behavior change.
> 
> Signed-off-by: Tejun Heo 

Makes sense
Reviewed-by: Michal Hocko 

> ---
>  kernel/cgroup_freezer.c | 48 ++--
>  1 file changed, 30 insertions(+), 18 deletions(-)
> 
> diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
> index 975b3d8..2690830 100644
> --- a/kernel/cgroup_freezer.c
> +++ b/kernel/cgroup_freezer.c
> @@ -247,45 +247,57 @@ static void unfreeze_cgroup(struct freezer *freezer)
>   cgroup_iter_end(cgroup, );
>  }
>  
> -static void freezer_change_state(struct freezer *freezer,
> -  enum freezer_state goal_state)
> +/**
> + * freezer_apply_state - apply state change to a single cgroup_freezer
> + * @freezer: freezer to apply state change to
> + * @freeze: whether to freeze or unfreeze
> + */
> +static void freezer_apply_state(struct freezer *freezer, bool freeze)
>  {
>   /* also synchronizes against task migration, see freezer_attach() */
> - spin_lock_irq(>lock);
> + lockdep_assert_held(>lock);
>  
> - switch (goal_state) {
> - case CGROUP_THAWED:
> - if (freezer->state != CGROUP_THAWED)
> - atomic_dec(_freezing_cnt);
> - freezer->state = CGROUP_THAWED;
> - unfreeze_cgroup(freezer);
> - break;
> - case CGROUP_FROZEN:
> + if (freeze) {
>   if (freezer->state == CGROUP_THAWED)
>   atomic_inc(_freezing_cnt);
>   freezer->state = CGROUP_FREEZING;
>   freeze_cgroup(freezer);
> - break;
> - default:
> - BUG();
> + } else {
> + if (freezer->state != CGROUP_THAWED)
> + atomic_dec(_freezing_cnt);
> + freezer->state = CGROUP_THAWED;
> + unfreeze_cgroup(freezer);
>   }
> +}
>  
> +/**
> + * freezer_change_state - change the freezing state of a cgroup_freezer
> + * @freezer: freezer of interest
> + * @freeze: whether to freeze or thaw
> + *
> + * Freeze or thaw @cgroup according to @freeze.
> + */
> +static void freezer_change_state(struct freezer *freezer, bool freeze)
> +{
> + /* update @freezer */
> + spin_lock_irq(>lock);
> + freezer_apply_state(freezer, freeze);
>   spin_unlock_irq(>lock);
>  }
>  
>  static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
>const char *buffer)
>  {
> - enum freezer_state goal_state;
> + bool freeze;
>  
>   if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0)
> - goal_state = CGROUP_THAWED;
> + freeze = false;
>   else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0)
> - goal_state = CGROUP_FROZEN;
> + freeze = true;
>   else
>   return -EINVAL;
>  
> - freezer_change_state(cgroup_freezer(cgroup), goal_state);
> + freezer_change_state(cgroup_freezer(cgroup), freeze);
>   return 0;
>  }
>  
> -- 
> 1.7.11.7
> 

-- 
Michal Hocko
SUSE Labs
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Re: [PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-08 Thread Michal Hocko 
On Sat 03-11-12 01:38:31, Tejun Heo wrote:
 * Make freezer_change_state() take bool @freeze instead of enum
   freezer_state.
 
 * Separate out freezer_apply_state() out of freezer_change_state().
   This makes freezer_change_state() a rather silly thin wrapper.  It
   will be filled with hierarchy handling later on.
 
 This patch doesn't introduce any behavior change.
 
 Signed-off-by: Tejun Heo t...@kernel.org

Makes sense
Reviewed-by: Michal Hocko mho...@suse.cz

 ---
  kernel/cgroup_freezer.c | 48 ++--
  1 file changed, 30 insertions(+), 18 deletions(-)
 
 diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
 index 975b3d8..2690830 100644
 --- a/kernel/cgroup_freezer.c
 +++ b/kernel/cgroup_freezer.c
 @@ -247,45 +247,57 @@ static void unfreeze_cgroup(struct freezer *freezer)
   cgroup_iter_end(cgroup, it);
  }
  
 -static void freezer_change_state(struct freezer *freezer,
 -  enum freezer_state goal_state)
 +/**
 + * freezer_apply_state - apply state change to a single cgroup_freezer
 + * @freezer: freezer to apply state change to
 + * @freeze: whether to freeze or unfreeze
 + */
 +static void freezer_apply_state(struct freezer *freezer, bool freeze)
  {
   /* also synchronizes against task migration, see freezer_attach() */
 - spin_lock_irq(freezer-lock);
 + lockdep_assert_held(freezer-lock);
  
 - switch (goal_state) {
 - case CGROUP_THAWED:
 - if (freezer-state != CGROUP_THAWED)
 - atomic_dec(system_freezing_cnt);
 - freezer-state = CGROUP_THAWED;
 - unfreeze_cgroup(freezer);
 - break;
 - case CGROUP_FROZEN:
 + if (freeze) {
   if (freezer-state == CGROUP_THAWED)
   atomic_inc(system_freezing_cnt);
   freezer-state = CGROUP_FREEZING;
   freeze_cgroup(freezer);
 - break;
 - default:
 - BUG();
 + } else {
 + if (freezer-state != CGROUP_THAWED)
 + atomic_dec(system_freezing_cnt);
 + freezer-state = CGROUP_THAWED;
 + unfreeze_cgroup(freezer);
   }
 +}
  
 +/**
 + * freezer_change_state - change the freezing state of a cgroup_freezer
 + * @freezer: freezer of interest
 + * @freeze: whether to freeze or thaw
 + *
 + * Freeze or thaw @cgroup according to @freeze.
 + */
 +static void freezer_change_state(struct freezer *freezer, bool freeze)
 +{
 + /* update @freezer */
 + spin_lock_irq(freezer-lock);
 + freezer_apply_state(freezer, freeze);
   spin_unlock_irq(freezer-lock);
  }
  
  static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
const char *buffer)
  {
 - enum freezer_state goal_state;
 + bool freeze;
  
   if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0)
 - goal_state = CGROUP_THAWED;
 + freeze = false;
   else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0)
 - goal_state = CGROUP_FROZEN;
 + freeze = true;
   else
   return -EINVAL;
  
 - freezer_change_state(cgroup_freezer(cgroup), goal_state);
 + freezer_change_state(cgroup_freezer(cgroup), freeze);
   return 0;
  }
  
 -- 
 1.7.11.7
 

-- 
Michal Hocko
SUSE Labs
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Re: [PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-07 Thread Kamezawa Hiroyuki 

(2012/11/03 17:38), Tejun Heo wrote:

* Make freezer_change_state() take bool @freeze instead of enum
   freezer_state.

* Separate out freezer_apply_state() out of freezer_change_state().
   This makes freezer_change_state() a rather silly thin wrapper.  It
   will be filled with hierarchy handling later on.

This patch doesn't introduce any behavior change.

Signed-off-by: Tejun Heo 


Reviewed-by: KAMEZAWA Hiroyuki 


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Re: [PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-07 Thread Kamezawa Hiroyuki 

(2012/11/03 17:38), Tejun Heo wrote:

* Make freezer_change_state() take bool @freeze instead of enum
   freezer_state.

* Separate out freezer_apply_state() out of freezer_change_state().
   This makes freezer_change_state() a rather silly thin wrapper.  It
   will be filled with hierarchy handling later on.

This patch doesn't introduce any behavior change.

Signed-off-by: Tejun Heo t...@kernel.org


Reviewed-by: KAMEZAWA Hiroyuki kamezawa.hir...@jp.fujitsu.com


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[PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-03 Thread Tejun Heo 
* Make freezer_change_state() take bool @freeze instead of enum
  freezer_state.

* Separate out freezer_apply_state() out of freezer_change_state().
  This makes freezer_change_state() a rather silly thin wrapper.  It
  will be filled with hierarchy handling later on.

This patch doesn't introduce any behavior change.

Signed-off-by: Tejun Heo 
---
 kernel/cgroup_freezer.c | 48 ++--
 1 file changed, 30 insertions(+), 18 deletions(-)

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 975b3d8..2690830 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -247,45 +247,57 @@ static void unfreeze_cgroup(struct freezer *freezer)
cgroup_iter_end(cgroup, );
 }
 
-static void freezer_change_state(struct freezer *freezer,
-enum freezer_state goal_state)
+/**
+ * freezer_apply_state - apply state change to a single cgroup_freezer
+ * @freezer: freezer to apply state change to
+ * @freeze: whether to freeze or unfreeze
+ */
+static void freezer_apply_state(struct freezer *freezer, bool freeze)
 {
/* also synchronizes against task migration, see freezer_attach() */
-   spin_lock_irq(>lock);
+   lockdep_assert_held(>lock);
 
-   switch (goal_state) {
-   case CGROUP_THAWED:
-   if (freezer->state != CGROUP_THAWED)
-   atomic_dec(_freezing_cnt);
-   freezer->state = CGROUP_THAWED;
-   unfreeze_cgroup(freezer);
-   break;
-   case CGROUP_FROZEN:
+   if (freeze) {
if (freezer->state == CGROUP_THAWED)
atomic_inc(_freezing_cnt);
freezer->state = CGROUP_FREEZING;
freeze_cgroup(freezer);
-   break;
-   default:
-   BUG();
+   } else {
+   if (freezer->state != CGROUP_THAWED)
+   atomic_dec(_freezing_cnt);
+   freezer->state = CGROUP_THAWED;
+   unfreeze_cgroup(freezer);
}
+}
 
+/**
+ * freezer_change_state - change the freezing state of a cgroup_freezer
+ * @freezer: freezer of interest
+ * @freeze: whether to freeze or thaw
+ *
+ * Freeze or thaw @cgroup according to @freeze.
+ */
+static void freezer_change_state(struct freezer *freezer, bool freeze)
+{
+   /* update @freezer */
+   spin_lock_irq(>lock);
+   freezer_apply_state(freezer, freeze);
spin_unlock_irq(>lock);
 }
 
 static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
 const char *buffer)
 {
-   enum freezer_state goal_state;
+   bool freeze;
 
if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0)
-   goal_state = CGROUP_THAWED;
+   freeze = false;
else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0)
-   goal_state = CGROUP_FROZEN;
+   freeze = true;
else
return -EINVAL;
 
-   freezer_change_state(cgroup_freezer(cgroup), goal_state);
+   freezer_change_state(cgroup_freezer(cgroup), freeze);
return 0;
 }
 
-- 
1.7.11.7

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[PATCH 5/9] cgroup_freezer: prepare freezer_change_state() for full hierarchy support

2012-11-03 Thread Tejun Heo 
* Make freezer_change_state() take bool @freeze instead of enum
  freezer_state.

* Separate out freezer_apply_state() out of freezer_change_state().
  This makes freezer_change_state() a rather silly thin wrapper.  It
  will be filled with hierarchy handling later on.

This patch doesn't introduce any behavior change.

Signed-off-by: Tejun Heo t...@kernel.org
---
 kernel/cgroup_freezer.c | 48 ++--
 1 file changed, 30 insertions(+), 18 deletions(-)

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 975b3d8..2690830 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -247,45 +247,57 @@ static void unfreeze_cgroup(struct freezer *freezer)
cgroup_iter_end(cgroup, it);
 }
 
-static void freezer_change_state(struct freezer *freezer,
-enum freezer_state goal_state)
+/**
+ * freezer_apply_state - apply state change to a single cgroup_freezer
+ * @freezer: freezer to apply state change to
+ * @freeze: whether to freeze or unfreeze
+ */
+static void freezer_apply_state(struct freezer *freezer, bool freeze)
 {
/* also synchronizes against task migration, see freezer_attach() */
-   spin_lock_irq(freezer-lock);
+   lockdep_assert_held(freezer-lock);
 
-   switch (goal_state) {
-   case CGROUP_THAWED:
-   if (freezer-state != CGROUP_THAWED)
-   atomic_dec(system_freezing_cnt);
-   freezer-state = CGROUP_THAWED;
-   unfreeze_cgroup(freezer);
-   break;
-   case CGROUP_FROZEN:
+   if (freeze) {
if (freezer-state == CGROUP_THAWED)
atomic_inc(system_freezing_cnt);
freezer-state = CGROUP_FREEZING;
freeze_cgroup(freezer);
-   break;
-   default:
-   BUG();
+   } else {
+   if (freezer-state != CGROUP_THAWED)
+   atomic_dec(system_freezing_cnt);
+   freezer-state = CGROUP_THAWED;
+   unfreeze_cgroup(freezer);
}
+}
 
+/**
+ * freezer_change_state - change the freezing state of a cgroup_freezer
+ * @freezer: freezer of interest
+ * @freeze: whether to freeze or thaw
+ *
+ * Freeze or thaw @cgroup according to @freeze.
+ */
+static void freezer_change_state(struct freezer *freezer, bool freeze)
+{
+   /* update @freezer */
+   spin_lock_irq(freezer-lock);
+   freezer_apply_state(freezer, freeze);
spin_unlock_irq(freezer-lock);
 }
 
 static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
 const char *buffer)
 {
-   enum freezer_state goal_state;
+   bool freeze;
 
if (strcmp(buffer, freezer_state_strs[CGROUP_THAWED]) == 0)
-   goal_state = CGROUP_THAWED;
+   freeze = false;
else if (strcmp(buffer, freezer_state_strs[CGROUP_FROZEN]) == 0)
-   goal_state = CGROUP_FROZEN;
+   freeze = true;
else
return -EINVAL;
 
-   freezer_change_state(cgroup_freezer(cgroup), goal_state);
+   freezer_change_state(cgroup_freezer(cgroup), freeze);
return 0;
 }
 
-- 
1.7.11.7

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