Re: [PATCH 5/6] drm/amdgpu: save the PD addr before scheduling the job

[zhoucm1 <david1.zhou@xxxxxxx>]

On 2016年06月16日 17:52, Christian König wrote:
> Am 16.06.2016 um 10:33 schrieb zhoucm1:
> > On 2016年06月15日 19:44, Christian König wrote:
> > > From: Christian König <christian.koenig@xxxxxxx>
> > >
> > > When we pipeline evictions the page directory could already be
> > > moving somewhere else when grab_id is called.
> > Isn't PD bo protected by job fence?
> > I think before job fence is signalled, the PD bo is safe, there 
> > shouldn't be a chance to evict PD bo.
>
> The crux here is that we start to pipeline BO evictions (we plan them 
> but don't execute them immediately).
>
> E.g. the eviction won't happen before the protecting fence is 
> signaled, but we have it planned and so the address returned by 
> amdgpu_bo_gpu_offset() is already the new one.
Thanks for mentioned, I see the code in ttm_bo_handle_move_mem:
    if (bo->mem.mm_node) {
        bo->offset = (bo->mem.start << PAGE_SHIFT) +
            bdev->man[bo->mem.mem_type].gpu_offset;
        bo->cur_placement = bo->mem.placement;
    } else
        bo->offset = 0;

it seems better to update the offset after the moving-fence is 
signalled, add a moving-fence callback?

Regards,
David Zhou
> Regards,
> Christian.
>
> > Regards,
> > David Zhou
> > > Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> > > ---
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 ++
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 6 ++----
> > >   2 files changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c 
> > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > > index a3d7d13..850c4dd 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> > > @@ -661,6 +661,8 @@ static int amdgpu_cs_ib_vm_chunk(struct 
> > > amdgpu_device *adev,
> > >           }
> > >       }
> > >   +    p->job->vm_pd_addr = amdgpu_bo_gpu_offset(vm->page_directory);
> > > +
> > >       r = amdgpu_bo_vm_update_pte(p, vm);
> > >       if (!r)
> > >           amdgpu_cs_sync_rings(p);
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
> > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > index d3e0576..82efb40 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > > @@ -177,7 +177,6 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, 
> > > struct amdgpu_ring *ring,
> > >                 struct amdgpu_sync *sync, struct fence *fence,
> > >                 unsigned *vm_id, uint64_t *vm_pd_addr)
> > >   {
> > > -    uint64_t pd_addr = amdgpu_bo_gpu_offset(vm->page_directory);
> > >       struct amdgpu_device *adev = ring->adev;
> > >       struct fence *updates = sync->last_vm_update;
> > >       struct amdgpu_vm_id *id, *idle;
> > > @@ -250,7 +249,7 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, 
> > > struct amdgpu_ring *ring,
> > >           if (atomic64_read(&id->owner) != vm->client_id)
> > >               continue;
> > >   -        if (pd_addr != id->pd_gpu_addr)
> > > +        if (*vm_pd_addr != id->pd_gpu_addr)
> > >               continue;
> > >             if (!same_ring &&
> > > @@ -298,14 +297,13 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, 
> > > struct amdgpu_ring *ring,
> > >       fence_put(id->flushed_updates);
> > >       id->flushed_updates = fence_get(updates);
> > >   -    id->pd_gpu_addr = pd_addr;
> > > +    id->pd_gpu_addr = *vm_pd_addr;
> > >         list_move_tail(&id->list, &adev->vm_manager.ids_lru);
> > >       atomic64_set(&id->owner, vm->client_id);
> > >       vm->ids[ring->idx] = id;
> > >         *vm_id = id - adev->vm_manager.ids;
> > > -    *vm_pd_addr = pd_addr;
> > >       trace_amdgpu_vm_grab_id(vm, ring->idx, *vm_id, *vm_pd_addr);
> > >     error:
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel