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Subject: Re: [PATCH v2 02/24] exec: Simplify unshare_files
To:     Arnd Bergmann <arnd@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     "Eric W. Biederman" <ebiederm@xmission.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Arnd Bergmann <arnd@arndb.de>
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From:   Geoff Levand <geoff@infradead.org>
Message-ID: <ed83033f-80af-5be0-ecbe-f2bf5c2075e9@infradead.org>
Date:   Tue, 24 Nov 2020 15:44:50 -0800
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On 11/24/20 12:14 PM, Arnd Bergmann wrote:
> On Tue, Nov 24, 2020 at 8:58 PM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>>
>> On Tue, Nov 24, 2020 at 11:55 AM Eric W. Biederman
>> <ebiederm@xmission.com> wrote:
>>>
>>> If cell happens to be dead we can remove a fair amount of generic kernel
>>> code that only exists to support cell.
>>
>> Even if some people might still use cell (which sounds unlikely), I
>> think we can remove the spu core dumping code.
> 
> The Cell blade hardware (arch/powerpc/platforms/cell/) that I'm listed
> as a maintainer for is very much dead, but there is apparently still some
> activity on the Playstation 3 that Geoff Levand maintains.
> 
> Eric correctly points out that the PS3 firmware no longer boots
> Linux (OtherOS), but AFAIK there are both users with old firmware
> and those that use a firmware exploit to run homebrew code including
> Linux.
> 
> I would assume they still use the SPU and might also use the core
> dump code in particular. Let's see what Geoff thinks.

There are still PS3-Linux users out there.  They use 'Homebrew' firmware
released through 'Hacker' forums that allow them to run Linux on
non-supported systems.  They are generally hobbies who don't post to
Linux kernel mailing lists.  I get direct inquiries regularly asking
about how to update to a recent kernel.  One of the things that attract
them to the PS3 is the Cell processor and either using or programming
the SPUs.

It is difficult to judge how much use the SPU core dump support gets,
but if it is not a cause of major problems I feel we should consider
keeping it.

-Geoff