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[PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper

Chen Ridong posted 1 patch 1 year, 6 months ago 
kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
[PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper
Posted by Chen Ridong 1 year, 6 months ago 
There are several functions to decrease attach_in_progress, and they
will wake up cpuset_attach_wq when attach_in_progress is zero. So,
add a helper to make it concise.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
 kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index d4322619e59a..c241845694ac 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -490,6 +490,17 @@ static inline void check_insane_mems_config(nodemask_t *nodes)
 	}
 }
 
+/*
+ * decrease cs->attach_in_progress.
+ * wake_up cpuset_attach_wq if cs->attach_in_progress==0.
+ */
+static inline void dec_attach_in_progress(struct cpuset *cs)
+{
+	cs->attach_in_progress--;
+	if (!cs->attach_in_progress)
+		wake_up(&cpuset_attach_wq);
+}
+
 /*
  * Cgroup v2 behavior is used on the "cpus" and "mems" control files when
  * on default hierarchy or when the cpuset_v2_mode flag is set by mounting
@@ -3421,9 +3432,7 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
 	cs = css_cs(css);
 
 	mutex_lock(&cpuset_mutex);
-	cs->attach_in_progress--;
-	if (!cs->attach_in_progress)
-		wake_up(&cpuset_attach_wq);
+	dec_attach_in_progress(cs);
 
 	if (cs->nr_migrate_dl_tasks) {
 		int cpu = cpumask_any(cs->effective_cpus);
@@ -3538,9 +3547,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 		reset_migrate_dl_data(cs);
 	}
 
-	cs->attach_in_progress--;
-	if (!cs->attach_in_progress)
-		wake_up(&cpuset_attach_wq);
+	dec_attach_in_progress(cs);
 
 	mutex_unlock(&cpuset_mutex);
 }
@@ -4284,9 +4291,7 @@ static void cpuset_cancel_fork(struct task_struct *task, struct css_set *cset)
 		return;
 
 	mutex_lock(&cpuset_mutex);
-	cs->attach_in_progress--;
-	if (!cs->attach_in_progress)
-		wake_up(&cpuset_attach_wq);
+	dec_attach_in_progress(cs);
 	mutex_unlock(&cpuset_mutex);
 }
 
@@ -4319,10 +4324,7 @@ static void cpuset_fork(struct task_struct *task)
 	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
 	cpuset_attach_task(cs, task);
 
-	cs->attach_in_progress--;
-	if (!cs->attach_in_progress)
-		wake_up(&cpuset_attach_wq);
-
+	dec_attach_in_progress(cs);
 	mutex_unlock(&cpuset_mutex);
 }
 
-- 
2.34.1
Re: [PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper
Posted by Kamalesh Babulal 1 year, 6 months ago 

On 7/25/24 7:25 AM, Chen Ridong wrote:
> There are several functions to decrease attach_in_progress, and they
> will wake up cpuset_attach_wq when attach_in_progress is zero. So,
> add a helper to make it concise.
> 
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
>  kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
>  1 file changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index d4322619e59a..c241845694ac 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -490,6 +490,17 @@ static inline void check_insane_mems_config(nodemask_t *nodes)
>  	}
>  }
>  
> +/*
> + * decrease cs->attach_in_progress.
> + * wake_up cpuset_attach_wq if cs->attach_in_progress==0.

In the description, adding locking constraint of cpuset_mutex would be helpful.
Something like "cpuset_mutex must be held by the caller."

> + */
> +static inline void dec_attach_in_progress(struct cpuset *cs)
> +{
> +	cs->attach_in_progress--;
> +	if (!cs->attach_in_progress)
> +		wake_up(&cpuset_attach_wq);
> +}
> +
>  /*
>   * Cgroup v2 behavior is used on the "cpus" and "mems" control files when
>   * on default hierarchy or when the cpuset_v2_mode flag is set by mounting
> @@ -3421,9 +3432,7 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
>  	cs = css_cs(css);
>  
>  	mutex_lock(&cpuset_mutex);
> -	cs->attach_in_progress--;
> -	if (!cs->attach_in_progress)
> -		wake_up(&cpuset_attach_wq);
> +	dec_attach_in_progress(cs);
>  
>  	if (cs->nr_migrate_dl_tasks) {
>  		int cpu = cpumask_any(cs->effective_cpus);
> @@ -3538,9 +3547,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
>  		reset_migrate_dl_data(cs);
>  	}
>  
> -	cs->attach_in_progress--;
> -	if (!cs->attach_in_progress)
> -		wake_up(&cpuset_attach_wq);
> +	dec_attach_in_progress(cs);
>  
>  	mutex_unlock(&cpuset_mutex);
>  }
> @@ -4284,9 +4291,7 @@ static void cpuset_cancel_fork(struct task_struct *task, struct css_set *cset)
>  		return;
>  
>  	mutex_lock(&cpuset_mutex);
> -	cs->attach_in_progress--;
> -	if (!cs->attach_in_progress)
> -		wake_up(&cpuset_attach_wq);
> +	dec_attach_in_progress(cs);
>  	mutex_unlock(&cpuset_mutex);
>  }
>  
> @@ -4319,10 +4324,7 @@ static void cpuset_fork(struct task_struct *task)
>  	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
>  	cpuset_attach_task(cs, task);
>  
> -	cs->attach_in_progress--;
> -	if (!cs->attach_in_progress)
> -		wake_up(&cpuset_attach_wq);
> -
> +	dec_attach_in_progress(cs);
>  	mutex_unlock(&cpuset_mutex);
>  }
>  

-- 
Thanks,
Kamalesh
Re: [PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper
Posted by chenridong 1 year, 6 months ago 

On 2024/7/25 19:01, Kamalesh Babulal wrote:
> 
> 
> On 7/25/24 7:25 AM, Chen Ridong wrote:
>> There are several functions to decrease attach_in_progress, and they
>> will wake up cpuset_attach_wq when attach_in_progress is zero. So,
>> add a helper to make it concise.
>>
>> Signed-off-by: Chen Ridong <chenridong@huawei.com>
>> ---
>>   kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
>>   1 file changed, 15 insertions(+), 13 deletions(-)
>>
>> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
>> index d4322619e59a..c241845694ac 100644
>> --- a/kernel/cgroup/cpuset.c
>> +++ b/kernel/cgroup/cpuset.c
>> @@ -490,6 +490,17 @@ static inline void check_insane_mems_config(nodemask_t *nodes)
>>   	}
>>   }
>>   
>> +/*
>> + * decrease cs->attach_in_progress.
>> + * wake_up cpuset_attach_wq if cs->attach_in_progress==0.
> 
> In the description, adding locking constraint of cpuset_mutex would be helpful.
> Something like "cpuset_mutex must be held by the caller."
> 
Thank you, I will to that.
>> + */
>> +static inline void dec_attach_in_progress(struct cpuset *cs)
>> +{
>> +	cs->attach_in_progress--;
>> +	if (!cs->attach_in_progress)
>> +		wake_up(&cpuset_attach_wq);
>> +}
>> +
>>   /*
>>    * Cgroup v2 behavior is used on the "cpus" and "mems" control files when
>>    * on default hierarchy or when the cpuset_v2_mode flag is set by mounting
>> @@ -3421,9 +3432,7 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
>>   	cs = css_cs(css);
>>   
>>   	mutex_lock(&cpuset_mutex);
>> -	cs->attach_in_progress--;
>> -	if (!cs->attach_in_progress)
>> -		wake_up(&cpuset_attach_wq);
>> +	dec_attach_in_progress(cs);
>>   
>>   	if (cs->nr_migrate_dl_tasks) {
>>   		int cpu = cpumask_any(cs->effective_cpus);
>> @@ -3538,9 +3547,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
>>   		reset_migrate_dl_data(cs);
>>   	}
>>   
>> -	cs->attach_in_progress--;
>> -	if (!cs->attach_in_progress)
>> -		wake_up(&cpuset_attach_wq);
>> +	dec_attach_in_progress(cs);
>>   
>>   	mutex_unlock(&cpuset_mutex);
>>   }
>> @@ -4284,9 +4291,7 @@ static void cpuset_cancel_fork(struct task_struct *task, struct css_set *cset)
>>   		return;
>>   
>>   	mutex_lock(&cpuset_mutex);
>> -	cs->attach_in_progress--;
>> -	if (!cs->attach_in_progress)
>> -		wake_up(&cpuset_attach_wq);
>> +	dec_attach_in_progress(cs);
>>   	mutex_unlock(&cpuset_mutex);
>>   }
>>   
>> @@ -4319,10 +4324,7 @@ static void cpuset_fork(struct task_struct *task)
>>   	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
>>   	cpuset_attach_task(cs, task);
>>   
>> -	cs->attach_in_progress--;
>> -	if (!cs->attach_in_progress)
>> -		wake_up(&cpuset_attach_wq);
>> -
>> +	dec_attach_in_progress(cs);
>>   	mutex_unlock(&cpuset_mutex);
>>   }
>>   
>
Re: [PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper
Posted by Waiman Long 1 year, 6 months ago 
On 7/25/24 07:40, chenridong wrote:
>
>
> On 2024/7/25 19:01, Kamalesh Babulal wrote:
>>
>>
>> On 7/25/24 7:25 AM, Chen Ridong wrote:
>>> There are several functions to decrease attach_in_progress, and they
>>> will wake up cpuset_attach_wq when attach_in_progress is zero. So,
>>> add a helper to make it concise.
>>>
>>> Signed-off-by: Chen Ridong <chenridong@huawei.com>
>>> ---
>>>   kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
>>>   1 file changed, 15 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
>>> index d4322619e59a..c241845694ac 100644
>>> --- a/kernel/cgroup/cpuset.c
>>> +++ b/kernel/cgroup/cpuset.c
>>> @@ -490,6 +490,17 @@ static inline void 
>>> check_insane_mems_config(nodemask_t *nodes)
>>>       }
>>>   }
>>>   +/*
>>> + * decrease cs->attach_in_progress.
>>> + * wake_up cpuset_attach_wq if cs->attach_in_progress==0.
>>
>> In the description, adding locking constraint of cpuset_mutex would 
>> be helpful.
>> Something like "cpuset_mutex must be held by the caller."
>>
> Thank you, I will to that.
>>> + */
>>> +static inline void dec_attach_in_progress(struct cpuset *cs)
>>> +{
>>> +    cs->attach_in_progress--;
>>> +    if (!cs->attach_in_progress)
>>> +        wake_up(&cpuset_attach_wq);
>>> +}
>>> +

I would suggested a dec_attach_in_progress_locked() and a 
dec_attach_in_progress() helpers. The dec_attach_in_progress() helper 
acquires the cpuset_mutex and call dec_attach_in_progress_locked(). 
Inside the dec_attach_in_progress_locked(), you can either add a comment 
about requiring cpuset_mutex held or add a 
lockdep_assert_held(&cpuset_mutex).

Cheers,
Longman
Re: [PATCH -next] cgroup/cpuset: add dec_attach_in_progress helper
Posted by chenridong 1 year, 6 months ago 

On 2024/7/26 3:07, Waiman Long wrote:
> 
> On 7/25/24 07:40, chenridong wrote:
>>
>>
>> On 2024/7/25 19:01, Kamalesh Babulal wrote:
>>>
>>>
>>> On 7/25/24 7:25 AM, Chen Ridong wrote:
>>>> There are several functions to decrease attach_in_progress, and they
>>>> will wake up cpuset_attach_wq when attach_in_progress is zero. So,
>>>> add a helper to make it concise.
>>>>
>>>> Signed-off-by: Chen Ridong <chenridong@huawei.com>
>>>> ---
>>>>   kernel/cgroup/cpuset.c | 28 +++++++++++++++-------------
>>>>   1 file changed, 15 insertions(+), 13 deletions(-)
>>>>
>>>> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
>>>> index d4322619e59a..c241845694ac 100644
>>>> --- a/kernel/cgroup/cpuset.c
>>>> +++ b/kernel/cgroup/cpuset.c
>>>> @@ -490,6 +490,17 @@ static inline void 
>>>> check_insane_mems_config(nodemask_t *nodes)
>>>>       }
>>>>   }
>>>>   +/*
>>>> + * decrease cs->attach_in_progress.
>>>> + * wake_up cpuset_attach_wq if cs->attach_in_progress==0.
>>>
>>> In the description, adding locking constraint of cpuset_mutex would 
>>> be helpful.
>>> Something like "cpuset_mutex must be held by the caller."
>>>
>> Thank you, I will to that.
>>>> + */
>>>> +static inline void dec_attach_in_progress(struct cpuset *cs)
>>>> +{
>>>> +    cs->attach_in_progress--;
>>>> +    if (!cs->attach_in_progress)
>>>> +        wake_up(&cpuset_attach_wq);
>>>> +}
>>>> +
> 
> I would suggested a dec_attach_in_progress_locked() and a 
> dec_attach_in_progress() helpers. The dec_attach_in_progress() helper 
> acquires the cpuset_mutex and call dec_attach_in_progress_locked(). 
> Inside the dec_attach_in_progress_locked(), you can either add a comment 
> about requiring cpuset_mutex held or add a 
> lockdep_assert_held(&cpuset_mutex).
> 
> Cheers,
> Longman
> 
> 
> 
Thanks, I will do that in v2.

Ridong

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