Am 10.11.2017 um 12:33 schrieb Roger He:
> since sometimes VRAM size is bigger than system memory
>
> Change-Id: I5b14d18ed7a9f79810cc50c023ac9e240bddf101
> Signed-off-by: Roger He <Hongbo.He at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index cdbdf67..f103ccc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1330,9 +1330,14 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
> DRM_INFO("amdgpu: %uM of VRAM memory ready\n",
> (unsigned) (adev->mc.real_vram_size / (1024 * 1024)));
>
> - if (amdgpu_gtt_size == -1)
> - gtt_size = max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
> - adev->mc.mc_vram_size);
> + if (amdgpu_gtt_size == -1) {
> + struct sysinfo si;
> +
> + si_meminfo(&si);
> + gtt_size = min(max((AMDGPU_DEFAULT_GTT_SIZE_MB << 20),
> + adev->mc.mc_vram_size),
> + ((uint64_t)si.totalram * si.mem_unit));
TTM starts to try to swap things out when more than 50% of system memory
are used, 75% is the default hard limit where it starts to block new
allocations.
So I would go with 75% here as well and code this as:
gtt_size = AMDGPU_DEFAULT_GTT_SIZE_MB << 20;
gtt_size = max(gtt_size, adev->mc.mc_vram_size);
gtt_size = min(gtt_size, ((uint64_t)si.totalram * si.mem_unit) * 75 / 100);
Regards,
Christian.
> +
> + }
> else
> gtt_size = (uint64_t)amdgpu_gtt_size << 20;
> r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_TT, gtt_size >> PAGE_SHIFT);
