Re: [PATCH 1/2] pinctrl: pinconf-generic: resize the pin config array directly

From: Linus Walleij
Date: Fri Nov 24 2023 - 05:07:09 EST


Hi Masahiro,

On Tue, Nov 21, 2023 at 11:21 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> On Tue, Nov 21, 2023 at 7:28 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> >
> > pinconf_generic_parse_dt_config() allocates memory that is large enough
> > to contain all the config parameters. Then, kmemdup() copies the found
> > configs to the memory with the exact size.
> >
> > There is no need to allocate memory twice; you can directly resize the
> > initial memory using krealloc_array().
> >
> > I also changed kcalloc() to kmalloc_array() to keep the consistency with
> > krealloc_array(). This change has no impact because you do not need to
> > zero out the 'cfg' array.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
>
> Sorry, I retract this patch set.
>
> krealloc() does not save any memory
> when the new_size is smaller than the current size.

But the first part where you switch to kmalloc_array() is still a nice change.

The fact that we use kmemdup to be able to also shrink the allocation is a
bit of an oddity I guess, but let's run this patch by Andy Shevchenko, and
ask what he thinks about simply introducing kmemdup_array() or if he
has other ideas for this.

Yours,
Linus Walleij