qemu-ppc
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v3] spapr: Add a new level of NUMA for GPUs


From: Daniel Henrique Barboza
Subject: Re: [PATCH v3] spapr: Add a new level of NUMA for GPUs
Date: Thu, 16 Jul 2020 13:40:19 -0300
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0



On 7/16/20 1:00 PM, Reza Arbab wrote:
On Thu, Jul 16, 2020 at 06:42:11AM -0300, Daniel Henrique Barboza wrote:
Which would translate here to:

       uint32_t associativity[] = {
           cpu_to_be32(0x4),
           cpu_to_be32(nvslot->numa_id),
           cpu_to_be32(nvslot->numa_id),
           cpu_to_be32(nvslot->numa_id),
           cpu_to_be32(nvslot->numa_id),
       };

Sure, that's how it originally was in v1 of the patch.

Yeah, Greg commented this in v2 about this chunk:

------------
This is a guest visible change. It should theoretically be controlled
with a compat property of the PHB (look for "static GlobalProperty" in
spapr.c). But since this code is only used for GPU passthrough and we
don't support migration of such devices, I guess it's okay. Maybe just
mention it in the changelog.
--------------

By all means you can mention in changelog/code comment why the associativity
of the GPU is nvslot->numa_id 4 times in a row, but I believe this
format is still clearer for us to understand. It also makes it equal
to skiboot.

And it deprecates the SPAPR_GPU_NUMA_ID macro, allowing us to use its value
(1) for other internal purposes regarding NUMA without collision with the
GPU semantics.



Thanks,


DHB



I'll send a v4 today. It's been a while so I need to rebase anyway.




reply via email to

[Prev in Thread] Current Thread [Next in Thread]