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Date: Fri, 22 Mar 2024 21:24:13 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Geoff Levand" <geoff@infradead.org>,
 "Geert Uytterhoeven" <geert@linux-m68k.org>,
 "Arnd Bergmann" <arnd@kernel.org>
Cc: llvm@lists.linux.dev, "Kevin Hao" <haokexin@gmail.com>,
 "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
 "Nick Desaulniers" <ndesaulniers@google.com>, linux-kernel@vger.kernel.org,
 "Nathan Chancellor" <nathan@kernel.org>,
 "Nicholas Piggin" <npiggin@gmail.com>,
 "Justin Stitt" <justinstitt@google.com>,
 "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>, linuxppc-dev@lists.ozlabs.org,
 "Bill Wendling" <morbo@google.com>
Subject: Re: [PATCH] powerpc: ps3: mark ps3_notification_device static for stack usage
Content-Type: text/plain

On Fri, Mar 22, 2024, at 09:34, Geoff Levand wrote:
> On 3/21/24 17:32, Geert Uytterhoeven wrote:
>> --- 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.

I didn't think it mattered much, given that you would rarely
have a kernel with PS3 support along with other platforms.

I suppose it does increase the size for a PS3-only kernel
as well, while your version makes it smaller.

> Here's what I came up with.  It builds for me without warnings.
> I haven't tested it yet.  A review would be appreciated.

It seems a little complicated but looks all correct to
me and reduces both stack and .data size, so

Acked-by: Arnd Bergmann <arnd@arndb.de>