Hi, The change looks good. I have commited it to Mesa.
Marek On Fri, Aug 31, 2012 at 6:57 PM, Vic Lee <llyzs....@gmail.com> wrote: > Hi, > > In my application, I need to read pixels back to system memory for every > rendered frame. My approach is to create a chain of textures with > PIPE_USAGE_STAGING flag, and copy the render target to the staging textures > before reading them to avoid pipeline stall. > > Now I found out as in the patch below, there's a line of code checking > whether the texture volume has more than 1024 pixels and will use a staging > texture if so. However the texture I am mapping is already staging and can > be surely mapped directly regardless of its volume. This checking does not > make any sense for me and is causing significant performance penalty. I have > tried removing it and nothing is broken, performance can go up 10-20% in my > case. > > Please point it out if I missed anything here, otherwise I suggest this two > lines of code should be removed. > > Thanks in advanced. > > Vic > > diff --git a/src/gallium/drivers/r600/r600_texture.c > b/src/gallium/drivers/r600/r600_texture.c > index 6de3d6a..536f88f 100644 > --- a/src/gallium/drivers/r600/r600_texture.c > +++ b/src/gallium/drivers/r600/r600_texture.c > @@ -622,9 +622,6 @@ struct pipe_transfer* r600_texture_get_transfer(struct > pipe_context *ctx, > use_staging_texture = TRUE; > } > > - if ((usage & PIPE_TRANSFER_READ) && u_box_volume(box) > 1024) > - use_staging_texture = TRUE; > - > /* Use a staging texture for uploads if the underlying BO is busy. > */ > if (!(usage & PIPE_TRANSFER_READ) && > (rctx->ws->cs_is_buffer_referenced(rctx->cs, > rtex->resource.cs_buf, RADEON_USAGE_READWRITE) || > > Vic > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
