TTM itself has some logic for need_dma32 and TTM_PAGE_FLAG_DMA32. I believe that should already handle this. need_dma32 is passed from amdgpu to ttm_bo_device_init to bdev->need_dma32. ttm_tt_create translates that to page_flags |= TTM_PAGE_FLAG_DMA32 and passes that to bdev->driver->ttm_tt_create. The two page allocators in ttm_page_alloc.c and ttm_page_alloc_dma.c check ttm->page_flags. Is that chain broken somewhere? Overriding glob->mem_glob->num_zones from amdgpu seems to be a bit of a hack. Regards, Felix On 2019-06-12 8:13, Yang, Philip wrote: > TTM create two zones, kernel zone and dma32 zone for system memory. If > system memory address allocated is below 4GB, this account to dma32 zone > and will exhaust dma32 zone and trigger unnesssary TTM eviction. > > Patch "drm/ttm: Account for kernel allocations in kernel zone only" only > handle the allocation for acc_size, the system memory page allocation is > through ttm_mem_global_alloc_page which still account to dma32 zone if > page is below 4GB. > > Change-Id: I289b85d891b8f64a1422c42b1eab398098ab7ef7 > Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > index 2778ff63d97d..79bb9dfe617b 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c > @@ -1686,6 +1686,10 @@ int amdgpu_ttm_init(struct amdgpu_device *adev) > } > adev->mman.initialized = true; > > + /* Only kernel zone (no dma32 zone) if device does not require dma32 */ > + if (!adev->need_dma32) > + adev->mman.bdev.glob->mem_glob->num_zones = 1; > + > /* We opt to avoid OOM on system pages allocations */ > adev->mman.bdev.no_retry = true; > _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
