[PATCH] workqueue: Introduce from_wq() helper for cleaner callback declarations

[PATCH] workqueue: Introduce from_wq() helper for cleaner callback declarations

[Allen Pais]

To streamline the transition from tasklets to worqueues, a new helper
function, from_wq(), is introduced. This helper, inspired by existing
from_() patterns, utilizes container_of() and eliminates the redundancy
of declaring variable types, leading to more concise and readable code.

The modified code snippet demonstrates the enhanced clarity achieved
with from_wq():

  void callback(struct work_struct *w)
   {
     - struct some_data_structure *local = container_of(w,
						       struct some_data_structure,
						       work);
     + struct some_data_structure *local = from_wq(local, w, work);

This change aims to facilitate a smoother transition and uphold code
quality standards.

Based on:
  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git disable_work-v3

Signed-off-by: Allen Pais <allen.lkml@gmail.com>
---
 include/linux/workqueue.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 7710cd52f7f0..aa61009c6fd6 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -527,6 +527,9 @@ alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);
 #define create_singlethread_workqueue(name)				\
 	alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
 
+#define from_wq(var, callback_work, work_fieldname)	\
+	container_of(callback_work, typeof(*var), work_fieldname)
+
 extern void destroy_workqueue(struct workqueue_struct *wq);
 
 struct workqueue_attrs *alloc_workqueue_attrs(void);
-- 
2.17.1

Re: [PATCH] workqueue: Introduce from_wq() helper for cleaner callback declarations

[Tejun Heo]

On Tue, Feb 27, 2024 at 06:56:28PM +0000, Allen Pais wrote:
> To streamline the transition from tasklets to worqueues, a new helper
> function, from_wq(), is introduced. This helper, inspired by existing
> from_() patterns, utilizes container_of() and eliminates the redundancy
> of declaring variable types, leading to more concise and readable code.
> 
> The modified code snippet demonstrates the enhanced clarity achieved
> with from_wq():
> 
>   void callback(struct work_struct *w)
>    {
>      - struct some_data_structure *local = container_of(w,
> 						       struct some_data_structure,
> 						       work);
>      + struct some_data_structure *local = from_wq(local, w, work);

I'm not necessarily against it but it's a bit meh in terms of how much it
saves. Also, can you please name it from_work()?

Thanks.

-- 
tejun

Re: [PATCH] workqueue: Introduce from_wq() helper for cleaner callback declarations

[Allen Pais]

> 
> 
> On Tue, Feb 27, 2024 at 06:56:28PM +0000, Allen Pais wrote:
>> To streamline the transition from tasklets to worqueues, a new helper
>> function, from_wq(), is introduced. This helper, inspired by existing
>> from_() patterns, utilizes container_of() and eliminates the redundancy
>> of declaring variable types, leading to more concise and readable code.
>> 
>> The modified code snippet demonstrates the enhanced clarity achieved
>> with from_wq():
>> 
>>  void callback(struct work_struct *w)
>>   {
>>     - struct some_data_structure *local = container_of(w,
>> 						       struct some_data_structure,
>> 						       work);
>>     + struct some_data_structure *local = from_wq(local, w, work);
> 
> I'm not necessarily against it but it's a bit meh in terms of how much it
> saves. Also, can you please name it from_work()?

  I agree :). It does help a little in conversion. Sure, will send out a v2 right away.

Thanks.

> 
> Thanks.
> 
> -- 
> tejun