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[PATCH 1/3] delayacct: introduce delayacct_enabled() to simplify implement

brookxu.cn posted 3 patches 2 years, 2 months ago
[PATCH 1/3] delayacct: introduce delayacct_enabled() to simplify implement
Posted by brookxu.cn 2 years, 2 months ago 
From: Chunguang Xu <chunguang.xu@shopee.com>

Introduce delayacct_enabled() to simplify the code and make it
more concise.

Signed-off-by: Chunguang Xu <chunguang.xu@shopee.com>
---
 include/linux/delayacct.h | 74 +++++++++++----------------------------
 kernel/delayacct.c        |  2 +-
 2 files changed, 21 insertions(+), 55 deletions(-)

diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 6639f48dac36..660e534ce7c4 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -94,137 +94,103 @@ static inline void delayacct_tsk_init(struct task_struct *tsk)
 		__delayacct_tsk_init(tsk);
 }
 
+static inline bool delayacct_enabled(void)
+{
+	return static_branch_unlikely(&delayacct_key);
+}
+
 /* Free tsk->delays. Called from bad fork and __put_task_struct
  * where there's no risk of tsk->delays being accessed elsewhere
  */
 static inline void delayacct_tsk_free(struct task_struct *tsk)
 {
-	if (tsk->delays)
+	if (delayacct_enabled())
 		kmem_cache_free(delayacct_cache, tsk->delays);
 	tsk->delays = NULL;
 }
 
 static inline void delayacct_blkio_start(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_blkio_start();
 }
 
 static inline void delayacct_blkio_end(struct task_struct *p)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (p->delays)
+	if (delayacct_enabled())
 		__delayacct_blkio_end(p);
 }
 
 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
 {
-	if (tsk->delays)
+	if (delayacct_enabled())
 		return __delayacct_blkio_ticks(tsk);
 	return 0;
 }
 
 static inline void delayacct_freepages_start(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_freepages_start();
 }
 
 static inline void delayacct_freepages_end(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_freepages_end();
 }
 
 static inline void delayacct_thrashing_start(bool *in_thrashing)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_thrashing_start(in_thrashing);
 }
 
 static inline void delayacct_thrashing_end(bool *in_thrashing)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_thrashing_end(in_thrashing);
 }
 
 static inline void delayacct_swapin_start(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_swapin_start();
 }
 
 static inline void delayacct_swapin_end(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_swapin_end();
 }
 
 static inline void delayacct_compact_start(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_compact_start();
 }
 
 static inline void delayacct_compact_end(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_compact_end();
 }
 
 static inline void delayacct_wpcopy_start(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_wpcopy_start();
 }
 
 static inline void delayacct_wpcopy_end(void)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (current->delays)
+	if (delayacct_enabled())
 		__delayacct_wpcopy_end();
 }
 
 static inline void delayacct_irq(struct task_struct *task, u32 delta)
 {
-	if (!static_branch_unlikely(&delayacct_key))
-		return;
-
-	if (task->delays)
+	if (delayacct_enabled())
 		__delayacct_irq(task, delta);
 }
 
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index 6f0c358e73d8..ce10b7c1ee43 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -161,7 +161,7 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
 	d->cpu_run_virtual_total =
 		(tmp < (s64)d->cpu_run_virtual_total) ?	0 : tmp;
 
-	if (!tsk->delays)
+	if (!delayacct_enabled())
 		return 0;
 
 	/* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
-- 
2.25.1
Re: [PATCH 1/3] delayacct: introduce delayacct_enabled() to simplify implement
Posted by Peter Zijlstra 2 years, 2 months ago 
On Sun, Oct 08, 2023 at 06:49:36PM +0800, brookxu.cn wrote:
> From: Chunguang Xu <chunguang.xu@shopee.com>
> 
> Introduce delayacct_enabled() to simplify the code and make it
> more concise.
> 
> Signed-off-by: Chunguang Xu <chunguang.xu@shopee.com>
> ---
>  include/linux/delayacct.h | 74 +++++++++++----------------------------
>  kernel/delayacct.c        |  2 +-
>  2 files changed, 21 insertions(+), 55 deletions(-)
> 
> diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
> index 6639f48dac36..660e534ce7c4 100644
> --- a/include/linux/delayacct.h
> +++ b/include/linux/delayacct.h
> @@ -94,137 +94,103 @@ static inline void delayacct_tsk_init(struct task_struct *tsk)
>  		__delayacct_tsk_init(tsk);
>  }
>  
> +static inline bool delayacct_enabled(void)
> +{
> +	return static_branch_unlikely(&delayacct_key);
> +}
> +
>  /* Free tsk->delays. Called from bad fork and __put_task_struct
>   * where there's no risk of tsk->delays being accessed elsewhere
>   */
>  static inline void delayacct_tsk_free(struct task_struct *tsk)
>  {
> -	if (tsk->delays)
> +	if (delayacct_enabled())

This isn't an equivalent change and your Changelog does not clarify.
Re: [PATCH 1/3] delayacct: introduce delayacct_enabled() to simplify implement
Posted by brookxu 2 years, 2 months ago 
在 2023/10/8 18:56, Peter Zijlstra 写道:
> On Sun, Oct 08, 2023 at 06:49:36PM +0800, brookxu.cn wrote:
>> From: Chunguang Xu <chunguang.xu@shopee.com>
>>
>> Introduce delayacct_enabled() to simplify the code and make it
>> more concise.
>>
>> Signed-off-by: Chunguang Xu <chunguang.xu@shopee.com>
>> ---
>>   include/linux/delayacct.h | 74 +++++++++++----------------------------
>>   kernel/delayacct.c        |  2 +-
>>   2 files changed, 21 insertions(+), 55 deletions(-)
>>
>> diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
>> index 6639f48dac36..660e534ce7c4 100644
>> --- a/include/linux/delayacct.h
>> +++ b/include/linux/delayacct.h
>> @@ -94,137 +94,103 @@ static inline void delayacct_tsk_init(struct task_struct *tsk)
>>   		__delayacct_tsk_init(tsk);
>>   }
>>   
>> +static inline bool delayacct_enabled(void)
>> +{
>> +	return static_branch_unlikely(&delayacct_key);
>> +}
>> +
>>   /* Free tsk->delays. Called from bad fork and __put_task_struct
>>    * where there's no risk of tsk->delays being accessed elsewhere
>>    */
>>   static inline void delayacct_tsk_free(struct task_struct *tsk)
>>   {
>> -	if (tsk->delays)
>> +	if (delayacct_enabled())
> This isn't an equivalent change and your Changelog does not clarify.
Sorry, As Patch 2 will convert tsk->delays to object,  we donot need to 
check whether tsk->delays is null or not, so relative code can be simplify.

Patchew 2.1-devel-b67e4c2

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