[PATCH 2/2] drm/amdgpu: use GTT only as fallback for VRAM|GTT

[Bhardwaj, Rajneesh]

[AMD Official Use Only - General]

-----Original Message-----
From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Hamza Mahfooz
Sent: Monday, November 27, 2023 10:53 AM
To: Christian König <ckoenig.leichtzumerken at gmail.com>; jani.nikula at linux.intel.com; kherbst at redhat.com; dakr at redhat.com; zackr at vmware.com; Olsak, Marek <Marek.Olsak at amd.com>; linux-graphics-maintainer at vmware.com; amd-gfx at lists.freedesktop.org; nouveau at lists.freedesktop.org; intel-gfx at lists.freedesktop.org; virtualization at lists.linux.dev; spice-devel at lists.freedesktop.org; dri-devel at lists.freedesktop.org
Subject: Re: [PATCH 2/2] drm/amdgpu: use GTT only as fallback for VRAM|GTT

On 11/27/23 09:54, Christian König wrote:
> Try to fill up VRAM as well by setting the busy flag on GTT allocations.
>
> This fixes the issue that when VRAM was evacuated for suspend it's
> never filled up again unless the application is restarted.

I found the subject description a bit misleading. Maybe use a Fixes tag describing it is a fix for suspend resume regression other than that, looks good to me.

Acked-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>

>

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2893

> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index aa0dd6dad068..ddc8fb4db678 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -173,6 +173,12 @@ void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain)
>                       abo->flags & AMDGPU_GEM_CREATE_PREEMPTIBLE ?
>                       AMDGPU_PL_PREEMPT : TTM_PL_TT;
>               places[c].flags = 0;
> +             /*
> +              * When GTT is just an alternative to VRAM make sure that we
> +              * only use it as fallback and still try to fill up VRAM first.
> +              */
> +             if (domain & AMDGPU_GEM_DOMAIN_VRAM)
> +                     places[c].flags |= TTM_PL_FLAG_BUSY;
>               c++;
>       }
>
--
Hamza