[PATCH v3 05/29] arc: Add <bits/pagesize.h>

[Florian Weimer]

* Florian Weimer:

> * Vineet Gupta:
>
>> On 9/29/24 08:59, Florian Weimer wrote:
>>> According to arch/arc/Kconfig in the Linux kernel sources, arc
>>> supports pagge sizes 4 KiB, 8 KiB, 16 KiB.  However,
>>> the toolchain defaults are not compatible with 16 KiB pages, so
>>> xfail the future elf/tst-load-alignment test.
>>>
>>> (Note: Alternatively, we could fix the maximum page size at 8 KiB,
>>> if that's closer to reality.)
>>
>> Indeed 16K size was more esoteric and dates back to older ARC700 cpus
>> (not supported in glibc anyways) And 8K is indeed the default for
>> ARCompact and ARCv2 ISA cores.
>
>>> +#define __GLIBC_PAGE_SHIFT_MIN 12
>>> +#define __GLIBC_PAGE_SHIFT_MAX 14
>
> Do you suggest to change the maximum shift to 13?  Sorry, it's not clear
> based on your comment.

I'm going to keep it at 12 because as Richard Henderson pointed out (for
the similar alpha situation), only the minimum == maxmimum case can be
optimized.  And sticking with a 4K minimum helps qemu-user, apparently.

Thanks,
Florian