Re: [PATCH 0/2 v4] drivers: arch_topology: introduce automatic cleanup feature

[Vincenzo Mezzela]

On 13/05/24 12:02, Sudeep Holla wrote:
> On Mon, May 13, 2024 at 10:13:02AM +0200, Vincenzo Mezzela wrote:
> > This patch series introduces the automatic cleanup feature using the __free
> > attribute. With this modification, resources allocated with __free are
> > automatically released at the end of the scope.
> >
> > In some cases, modifying the structure of loops is necessary to utilize the
> > __free attribute effectively. For example:
> >
> > ```
> > struct device_node *t;
> >
> > do {
> >      t = of_get_child_by_name(..);
> >      if (t) {
> >
> >          // some code here
> >
> >          of_node_put(t);
> >      }
> >      i++;
> >
> > } while (t);
> >
> > //       ^
> > //       |
> > //  device_node here
> > ```
> >
> > To use the __free attribute here, we need to move the declaration of the device_node
> > within the loop, otherwise the automatic cleanup is called only at the end of the
> > function, and not at end of each iteration of the loop, being it scope-based.
> >
> > However, moving the declaration of the device_node within the loop, we can no
> > longer check the exit condition in the loop statement, being it outside
> > the loop's scope.
> >
> > Therefore, this work is split into two patches. The first patch moves the exit
> > condition of the loop directly within the loop's scope with an explicit break
> > statement:
> >
> > ```
> > struct device_node *t;
> >
> > do {
> >      t = of_get_child_by_name(..);
> >      if (!t)
> >          break;
> >
> >      // some code here
> >
> >      of_node_put(t);
> >      i++;
> >
> > } while (1);
> > ```
> > The second patch eliminates all of_node_put() calls, introducing the __free
> > attribute to the device_node.
> >
> >
> > changes in v2:
> >      - check loop exit condition within the loop
> >      - add cleanup.h header
> >
> > changes in v3:
> >      - split patch in two
> >      - fix misalignment
> >      - fix checkpatch warnings
> >      - replace break with return statement where possible
> >
> > changes in v4:
> >      - fix commit subject
> >      - fix coding style
> Looks good now to me.
>
> Acked-by: Sudeep Holla<sudeep.holla@xxxxxxx>
>
> It is merge window now, so there is a chance that it may get lost. You
> may have to post it again at -rc1. Greg can then pick it up for v6.11
>
> --
> Regards,t
> Sudeep

Hi Greg,

hope this message finds you well. I wanted to kindly follow up on the 
patch [1] I
submitted to introduce the __free attribute in drivers/base/arch_topology.c

Thanks,

Vincenzo

- [1] 
https://lore.kernel.org/lkml/20240513081304.499915-1-vincenzo.mezzela@xxxxxxxxx/