Re: [PATCH] powerpc: ps3: mark ps3_notification_device static for stack usage

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Arnd,

On Wed, Mar 20, 2024 at 7:03 PM Arnd Bergmann <arnd@kernel.org> wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> The device is way too large to be on the stack, causing a warning for
> an allmodconfig build with clang:
>
> arch/powerpc/platforms/ps3/device-init.c:771:12: error: stack frame size (2064) exceeds limit (2048) in 'ps3_probe_thread' [-Werror,-Wframe-larger-than]
>   771 | static int ps3_probe_thread(void *data)
>
> There is only a single thread that ever accesses this, so it's fine to
> make it static, which avoids the warning.
>
> Fixes: b4cb2941f855 ("[POWERPC] PS3: Use the HVs storage device notification mechanism properly")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for your patch!

> --- a/arch/powerpc/platforms/ps3/device-init.c
> +++ b/arch/powerpc/platforms/ps3/device-init.c
> @@ -770,7 +770,7 @@ static struct task_struct *probe_task;
>
>  static int ps3_probe_thread(void *data)
>  {
> -       struct ps3_notification_device dev;
> +       static struct ps3_notification_device dev;
>         int res;
>         unsigned int irq;
>         u64 lpar;

Making it static increases kernel size for everyone.  So I'd rather
allocate it dynamically. The thread already allocates a buffer, which
can be replaced at no cost by allocating a structure containing both
the ps3_notification_device and the buffer.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds