Re: [PATCH][RFC] io_uring: Fix io_uring_mmu_get_unmapped_area() for IA-64

[Helge Deller <deller@gmx.de>]

On 7/21/23 00:30, Jens Axboe wrote:
> On 7/19/23 3:20?PM, Helge Deller wrote:
>> The io_uring testcase is broken on IA-64 since commit d808459b2e31
>> ("io_uring: Adjust mapping wrt architecture aliasing requirements").
>>
>> The reason is, that this commit introduced an own architecture
>> independend get_unmapped_area() search algorithm which doesn't suite the
>> memory region requirements for IA-64.
>>
>> To avoid similar problems in the future it's better to switch back to
>> the architecture-provided get_unmapped_area() function and adjust the
>> needed input parameters before the call.  Additionally
>> io_uring_mmu_get_unmapped_area() will now become easier to understand
>> and maintain.
>>
>> This patch has been tested on physical IA-64 and PA-RISC machines,
>> without any failures in the io_uring testcases. On PA-RISC the
>> LTP mmmap testcases did not report any regressions either.
>>
>> I don't expect issues for other architectures, but it would be nice if
>> this patch could be tested on other machines too.
>
> Any comments from the IA64 folks?

matoro tested it on ia64 at least...

> Helge, should this be split into three patches? One for hppa, one for
> ia64, and then the io_uring one?

If we split up, I would prefer to split it into 2 patches:
One for io_uring together with the hppa patch, since they should go in together.

The ia64 patch is probably unrelated, and can go seperately. But
there doesn't seem to be any ia64 maintainer...?

Do you have a chance to test this patch on the other io_uring platforms,
without applying it into your tree? I think some testing would be good.

Helge