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

John David Anglin
2023-03-15T21:05:52Z

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.

/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.
>
> commit 4c4fd1843bf284c0063c3a0f8822cb2d352b20c0 (origin/master, origin/HEAD, master)
> Author: Jens Axboe<axboe@kernel.dk>
> Date: Wed Mar 15 11:34:54 2023 -0600
>
> test/file-verify: add dcache sync for parisc
>
> then please experiment with that. 64 might be the correct value here and
> I just got lucky with my testing...
> be interesting to see

--
John David Anglin dave.anglin@bell.net