Re: [PATCH 3/3] drm/amdgpu: skip kfd resume_process for dev_pm_ops.thaw()

["Christian König" <christian.koenig@amd.com>]

On 30.06.25 12:41, Samuel Zhang wrote:
> The hibernation successful workflow:
> - prepare: evict VRAM and swapout GTT BOs
> - freeze
> - create the hibernation image in system memory
> - thaw: swapin and restore BOs

Why should a thaw happen here in between?

> - complete
> - write hibernation image to disk
> - amdgpu_pci_shutdown
> - goto S5, turn off the system.
> 
> During prepare stage of hibernation, VRAM and GTT BOs will be swapout to
> shmem. Then in thaw stage, all BOs will be swapin and restored.

That's not correct. This is done by the application starting again and not during thaw.

> 
> On server with 192GB VRAM * 8 dGPUs and 1.7TB system memory,
> the swapin and restore BOs takes too long (50 minutes) and it is not
> necessary since the follow-up stages does not use GPU.
> 
> This patch is to skip BOs restore during thaw to reduce the hibernation
> time.

As far as I can see that doesn't make sense. The KFD processes need to be resumed here and that can't be skipped.

Regards,
Christian.

> 
> Signed-off-by: Samuel Zhang <guoqing.zhang@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c    | 2 ++
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index a8f4697deb1b..b550d07190a2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5328,7 +5328,7 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>  		amdgpu_virt_init_data_exchange(adev);
>  		amdgpu_virt_release_full_gpu(adev, true);
>  
> -		if (!adev->in_s0ix && !r && !adev->in_runpm)
> +		if (!adev->in_s0ix && !r && !adev->in_runpm && !adev->in_s4)
>  			r = amdgpu_amdkfd_resume_process(adev);
>  	}
>  
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 571b70da4562..23b76e8ac2fd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -2734,7 +2734,9 @@ static int amdgpu_pmops_poweroff(struct device *dev)
>  static int amdgpu_pmops_restore(struct device *dev)
>  {
>  	struct drm_device *drm_dev = dev_get_drvdata(dev);
> +	struct amdgpu_device *adev = drm_to_adev(drm_dev);
>  
> +	adev->in_s4 = false;
>  	return amdgpu_device_resume(drm_dev, true);
>  }
>