linux-kernel - Re: [PATCH] drm/amdgpu: Mark contexts guilty for any reset type

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Message-ID: <717b333b-7af6-063e-d50d-bb2b3bbcecb4@igalia.com>
Date:   Mon, 24 Apr 2023 10:26:33 -0300
From:   André Almeida <andrealmeid@...lia.com>
To:     Christian König <christian.koenig@....com>
Cc:     kernel-dev@...lia.com, alexander.deucher@....com,
        pierre-eric.pelloux-prayer@....com,
        'Marek Olšák' <maraeo@...il.com>,
        linux-kernel@...r.kernel.org, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org,
        "Tuikov, Luben" <Luben.Tuikov@....com>
Subject: Re: [PATCH] drm/amdgpu: Mark contexts guilty for any reset type

Hi Christian, thank you for your comments.

Em 24/04/2023 04:03, Christian König escreveu:
> Am 24.04.23 um 03:43 schrieb André Almeida:
>> When a DRM job timeout, the GPU is probably hang and amdgpu have some
>> ways to deal with that, ranging from soft recoveries to full device
>> reset. Anyway, when userspace ask the kernel the state of the context
>> (via AMDGPU_CTX_OP_QUERY_STATE), the kernel reports that the device was
>> reset, regardless if a full reset happened or not.
>>
>> However, amdgpu only marks a context guilty in the ASIC reset path. This
>> makes the userspace report incomplete, given that on soft recovery path
>> the guilty context is not told that it's the guilty one.
>>
>> Fix this by marking the context guilty for every type of reset when a
>> job timeouts.
> 
> The guilty handling is pretty much broken by design and only works 
> because we go through multiple hops of validating the entity after the 
> job has already been pushed to the hw.

I see, thanks.

> 
> I think we should probably just remove that completely and use an 
> approach where we check the in flight submissions in the query state 
> IOCTL.

Like the DRM_IOCTL_I915_GET_RESET_STATS approach?

 > See my other patch on the mailing list regarding that.

Which one, the "[PATCH 1/8] drm/scheduler: properly forward fence 
errors" series?

> 
> Additional to that I currently didn't considered soft-recovered 
> submissions as fatal and continue accepting submissions from that 
> context, but already wanted to talk with Marek about that behavior.
> 

Interesting. I will try to test and validate this approach to see if the 
contexts keep working as expected on soft-resets.

> Regards,
> Christian.