On 15/07/2020 12:50, Chris Wilson wrote:
We need to make the DMA allocations used for page directories to be performed up front so that we can include those allocations in our memory reservation pass. The downside is that we have to assume the worst case, even before we know the final layout, and always allocate enough page directories for this object, even when there will be overlap. This unfortunately can be quite expensive, especially as we have to clear/reset the page directories and DMA pages, but it should only be required during early phases of a workload when new objects are being discovered, or after memory/eviction pressure when we need to rebind. Once we reach steady state, the objects should not be moved and we no longer need to preallocating the pages tables. It should be noted that the lifetime for the page directories DMA is more or less decoupled from individual fences as they will be shared across objects across timelines. v2: Only allocate enough PD space for the PTE we may use, we do not need to allocate PD that will be left as scratch. v3: Store the shift unto the first PD level to encapsulate the different PTE counts for gen6/gen8. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Fwiw, Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx> _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
