[Mesa-dev] [PATCH v2 34/37] panfrost: Do fine-grained flushing when preparing BO for CPU accesses

[Alyssa Rosenzweig]

R-b

On Mon, Sep 16, 2019 at 11:37:12AM +0200, Boris Brezillon wrote:
> We don't have to flush all batches when we're only interested in
> reading/writing a specific BO. Thanks to the
> panfrost_flush_batches_accessing_bo() and panfrost_bo_wait() helpers
> we can now flush only the batches touching the BO we want to access
> from the CPU.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> ---
>  src/gallium/drivers/panfrost/pan_resource.c | 27 +++++++++------------
>  1 file changed, 12 insertions(+), 15 deletions(-)
> 
> diff --git a/src/gallium/drivers/panfrost/pan_resource.c b/src/gallium/drivers/panfrost/pan_resource.c
> index 1f7605adcd5d..d59529ff15b7 100644
> --- a/src/gallium/drivers/panfrost/pan_resource.c
> +++ b/src/gallium/drivers/panfrost/pan_resource.c
> @@ -578,10 +578,8 @@ panfrost_transfer_map(struct pipe_context *pctx,
>                          is_bound |= fb->cbufs[c]->texture == resource;
>          }
>  
> -        if (is_bound && (usage & PIPE_TRANSFER_READ)) {
> -                assert(level == 0);
> -                panfrost_flush_all_batches(ctx, true);
> -        }
> +        if (is_bound && (usage & PIPE_TRANSFER_READ))
> +                 assert(level == 0);
>  
>          /* TODO: Respect usage flags */
>  
> @@ -594,11 +592,11 @@ panfrost_transfer_map(struct pipe_context *pctx,
>                  /* No flush for writes to uninitialized */
>          } else if (!(usage & PIPE_TRANSFER_UNSYNCHRONIZED)) {
>                  if (usage & PIPE_TRANSFER_WRITE) {
> -                        /* STUB: flush reading */
> -                        //printf("debug: missed reading flush %d\n", resource->target);
> +                        panfrost_flush_batches_accessing_bo(ctx, bo, PAN_BO_GPU_ACCESS_RW);
> +                        panfrost_bo_wait(bo, INT64_MAX, PAN_BO_GPU_ACCESS_RW);
>                  } else if (usage & PIPE_TRANSFER_READ) {
> -                        /* STUB: flush writing */
> -                        //printf("debug: missed writing flush %d (%d-%d)\n", resource->target, box->x, box->x + box->width);
> +                        panfrost_flush_batches_accessing_bo(ctx, bo, PAN_BO_GPU_ACCESS_WRITE);
> +                        panfrost_bo_wait(bo, INT64_MAX, PAN_BO_GPU_ACCESS_WRITE);
>                  } else {
>                          /* Why are you even mapping?! */
>                  }
> @@ -748,11 +746,8 @@ panfrost_generate_mipmap(
>           * reorder-type optimizations in place. But for now prioritize
>           * correctness. */
>  
> -        struct panfrost_batch *batch = panfrost_get_batch_for_fbo(ctx);
> -        bool has_draws = batch->last_job.gpu;
> -
> -        if (has_draws)
> -                panfrost_flush_all_batches(ctx, true);
> +        panfrost_flush_batches_accessing_bo(ctx, rsrc->bo, PAN_BO_GPU_ACCESS_RW);
> +        panfrost_bo_wait(rsrc->bo, INT64_MAX, PAN_BO_GPU_ACCESS_RW);
>  
>          /* We've flushed the original buffer if needed, now trigger a blit */
>  
> @@ -765,8 +760,10 @@ panfrost_generate_mipmap(
>          /* If the blit was successful, flush once more. If it wasn't, well, let
>           * the state tracker deal with it. */
>  
> -        if (blit_res)
> -                panfrost_flush_all_batches(ctx, true);
> +        if (blit_res) {
> +                panfrost_flush_batches_accessing_bo(ctx, rsrc->bo, PAN_BO_GPU_ACCESS_WRITE);
> +                panfrost_bo_wait(rsrc->bo, INT64_MAX, PAN_BO_GPU_ACCESS_WRITE);
> +        }
>  
>          return blit_res;
>  }
> -- 
> 2.21.0