[Mesa-dev] [PATCH 1/4] r600g: use u_upload_mgr for allocating staging transfer buffers

[Aaron Watry]

I'm not familiar enough with the existing code to feel comfortable 
reviewing it, but I've run it through a full piglit test run (using 
tests/all.tests w/ GL/GLX enabled) without noticing any issues.

Also, Reaction Quake 3 performance went up by ~25% as a result of this 
series on my Radeon 6850.
http://openbenchmarking.org/result/1212102-SU-SUBALLOCT33

For my part:
Tested-by: Aaron Watry <awatry at gmail.com>

--Aaron Watry

> u_upload_mgr suballocates memory from a large buffer and maps the allocated
> range (unsychronized), which is perfect for short-lived staging buffers.
>
> This reduces the number of relocations sent to the kernel.
> ---
>   src/gallium/drivers/r600/r600_buffer.c |   30 +++++++++++++++---------------
>   1 file changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/src/gallium/drivers/r600/r600_buffer.c b/src/gallium/drivers/r600/r600_buffer.c
> index 9e2cf66..e674e13 100644
> --- a/src/gallium/drivers/r600/r600_buffer.c
> +++ b/src/gallium/drivers/r600/r600_buffer.c
> @@ -66,7 +66,8 @@ static void *r600_buffer_get_transfer(struct pipe_context *ctx,
>                                         unsigned usage,
>                                         const struct pipe_box *box,
>   				      struct pipe_transfer **ptransfer,
> -				      void *data, struct r600_resource *staging)
> +				      void *data, struct r600_resource *staging,
> +				      unsigned offset)
>   {
>   	struct r600_context *rctx = (struct r600_context*)ctx;
>   	struct r600_transfer *transfer = util_slab_alloc(&rctx->pool_transfers);
> @@ -77,8 +78,7 @@ static void *r600_buffer_get_transfer(struct pipe_context *ctx,
>   	transfer->transfer.box = *box;
>   	transfer->transfer.stride = 0;
>   	transfer->transfer.layer_stride = 0;
> -	transfer->staging = NULL;
> -	transfer->offset = 0;
> +	transfer->offset = offset;
>   	transfer->staging = staging;
>   	*ptransfer =&transfer->transfer;
>   	return data;
> @@ -147,18 +147,17 @@ static void *r600_buffer_transfer_map(struct pipe_context *ctx,
>   		if (rctx->ws->cs_is_buffer_referenced(rctx->cs, rbuffer->cs_buf, RADEON_USAGE_READWRITE) ||
>   		    rctx->ws->buffer_is_busy(rbuffer->buf, RADEON_USAGE_READWRITE)) {
>   			/* Do a wait-free write-only transfer using a temporary buffer. */
> -			struct r600_resource *staging = (struct r600_resource*)
> -				pipe_buffer_create(ctx->screen, PIPE_BIND_VERTEX_BUFFER,
> -						   PIPE_USAGE_STAGING,
> -						   box->width + (box->x % R600_MAP_BUFFER_ALIGNMENT));
> -			data = rctx->ws->buffer_map(staging->cs_buf, rctx->cs, PIPE_TRANSFER_WRITE);
> +			unsigned offset;
> +			struct r600_resource *staging = NULL;
>
> -			if (!data)
> -				return NULL;
> +			u_upload_alloc(rctx->uploader, 0, box->width + (box->x % R600_MAP_BUFFER_ALIGNMENT),
> +				&offset, (struct pipe_resource**)&staging, (void**)&data);
>
> -			data += box->x % R600_MAP_BUFFER_ALIGNMENT;
> -			return r600_buffer_get_transfer(ctx, resource, level, usage, box,
> -							ptransfer, data, staging);
> +			if (staging) {
> +				data += box->x % R600_MAP_BUFFER_ALIGNMENT;
> +				return r600_buffer_get_transfer(ctx, resource, level, usage, box,
> +								ptransfer, data, staging, offset);
> +			}
>   		}
>   	}
>
> @@ -169,7 +168,7 @@ static void *r600_buffer_transfer_map(struct pipe_context *ctx,
>   	data += box->x;
>
>   	return r600_buffer_get_transfer(ctx, resource, level, usage, box,
> -					ptransfer, data, NULL);
> +					ptransfer, data, NULL, 0);
>   }
>
>   static void r600_buffer_transfer_unmap(struct pipe_context *pipe,
> @@ -180,7 +179,8 @@ static void r600_buffer_transfer_unmap(struct pipe_context *pipe,
>
>   	if (rtransfer->staging) {
>   		struct pipe_box box;
> -		u_box_1d(transfer->box.x % R600_MAP_BUFFER_ALIGNMENT, transfer->box.width,&box);
> +		u_box_1d(rtransfer->offset + transfer->box.x % R600_MAP_BUFFER_ALIGNMENT,
> +			 transfer->box.width,&box);
>
>   		/* Copy the staging buffer into the original one. */
>   		r600_copy_buffer(pipe, transfer->resource, transfer->box.x,
> -- 
> 1.7.10.4
>