Re: [PATCHSET 0/5] User mapped provided buffer rings

Jens Axboe
2023-03-15T21:09:16Z

On 3/15/23 3:04?PM, John David Anglin wrote:
> On 2023-03-15 4:38 p.m., Jens Axboe wrote:
>> For file-verify.t, that one should work with the current tree. The issue
>> there is the use of registered buffers, and I added a parisc hack for
>> that. Maybe it's too specific to the PA8900 (the 128 byte stride). If
>> your tree does have:
> The 128 byte stride is only used on PA8800 and PA8900 processors. Other PA 2.0 processors
> use a 64 byte stride. PA 1.1 processors need a 32 byte stride.
>
> The following gcc defines are available: _PA_RISC2_0, _PA_RISC1_1 and _PA_RISC1_0.

Ah perfect!

> /proc/cpuinfo provides the CPU type but I'm not aware of any easy way to access the stride value
> from userspace. It's available from the PDC_CACHE call and it's used in the kernel.

model : 9000/785/C8000 - Crestone Peak Mako+ Slow [128]

I guess that's why it worked for me. OK, will ponder how to define that,
I think just going lowest common denominator is enough for now.

--
Jens Axboe