[Public]
> From: Yadav, Arvind <arvind.ya...@amd.com>
> Sent: Friday, April 25, 2025 3:21 PM
> To: Liang, Prike <prike.li...@amd.com>; amd-gfx@lists.freedesktop.org
> Cc: Deucher, Alexander <alexander.deuc...@amd.com>; Koenig, Christian
> <christian.koe...@amd.com>
> Subject: Re: [PATCH 1/3] drm/amdgpu: implicitly sync the dependent read fences
>
> This is problem for TLB flush. We should not do this changes. Here we are
> utilizing
> DMA_RESV_USAGE_BOOKKEEP due to the TLB flush fence associated with the
> page table (PT). We are ensuring that no page directory (PD) or page table
> (PT)
> should be free before flush and ttm bo release and delete both are also
> waiting for
> BOOKKEEP fence. Please drop this changes for eviction fence.
Thanks for sharing the background. So, we may need to test the fence whether is
an eviction fence in amdgpu_sync_test_fence () before added it to the VM sync.
Thanks,
Prike
> Regards,
> ~arvind
>
> On 4/25/2025 12:37 PM, Prike Liang wrote:
> > The driver doesn't want to sync on the DMA_RESV_USAGE_BOOKKEEP usage
> > fences, so here only return and sync the dependent read fences.
> >
> > Signed-off-by: Prike Liang <prike.li...@amd.com>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> > index 5576ed0b508f..4e1d30ecb6cc 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> > @@ -249,9 +249,8 @@ int amdgpu_sync_resv(struct amdgpu_device *adev,
> > struct amdgpu_sync *sync,
> >
> > if (resv == NULL)
> > return -EINVAL;
> > -
> > - /* TODO: Use DMA_RESV_USAGE_READ here */
> > - dma_resv_for_each_fence(&cursor, resv,
> DMA_RESV_USAGE_BOOKKEEP, f) {
> > + /*Only return and sync the fences of usage <=
> DMA_RESV_USAGE_READ.*/
> > + dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_READ, f) {
> > dma_fence_chain_for_each(f, f) {
> > struct dma_fence *tmp = dma_fence_chain_contained(f);
> >
