Could you please do this without changing u_upload_mgr? You can still use u_upload_alloc to allocate buffer memory in the driver and the map buffer read/write flags are not important with persistent coherent buffer mappings anyway.
Marek On Mon, Mar 3, 2014 at 9:29 PM, Niels Ole Salscheider <niels_...@salscheider-online.de> wrote: > Using the DMA engine for buffer downloads vastly improves performance. This is > because reads from VRAM by the CPU are slow because of the high latency of the > PCIe bus. > > The first patch allows u_upload_mgr to be used for downloads, too. The second > patch then uses u_upload_mgr in the radeon driver for downloads. > I considered to rename u_upload_mgr to u_transfer_mgr since it might be > confusing that an "upload manager" can be used for downloads. But then again > we > also have "transfers" so that u_transfer_mgr might also be confusing. Thus, I > decided not to rename it for now. > > Without these patches, the buffer_bandwidth benchmark from uCLbench gives me: > > ./buffer_bandwidth --size=20000000 --iterations=100 > # device 0: AMD BARTS // type gpu (192 MB global memory, 64 KB constant > memory, > 32 KB local memory) > 1/1 direct 20000000 Bytes 759.29 MB/s(HD) 17.13 MB/s(DD) > 14.61 MB/s(DH) > > With these paches, the read performance is much better: > > ./buffer_bandwidth --size=20000000 --iterations=100 > # device 0: AMD BARTS // type gpu (192 MB global memory, 64 KB constant > memory, > 32 KB local memory) > 1/1 direct 20000000 Bytes 759.90 MB/s(HD) 613.49 MB/s(DD) > 1841.07 MB/s(DH) > > Judging by these numbers, it might even make sense to use the DMA engine for > larger buffer downloads... > > Niels Ole Salscheider (2): > util/u_upload_mgr: Allow to also use it for downloads > radeon: Use transfer manager for buffer downloads > > src/gallium/auxiliary/hud/hud_context.c | 3 +- > src/gallium/auxiliary/util/u_blitter.c | 3 +- > src/gallium/auxiliary/util/u_upload_mgr.c | 49 +++++++++++----- > src/gallium/auxiliary/util/u_upload_mgr.h | 13 ++++- > src/gallium/auxiliary/util/u_vbuf.c | 3 +- > src/gallium/auxiliary/vl/vl_compositor.c | 3 +- > src/gallium/drivers/ilo/ilo_context.c | 3 +- > src/gallium/drivers/r300/r300_context.c | 3 +- > src/gallium/drivers/radeon/r600_buffer_common.c | 78 > +++++++++++++++++++------ > src/gallium/drivers/radeon/r600_pipe_common.c | 14 ++++- > src/gallium/drivers/radeon/r600_pipe_common.h | 1 + > src/mesa/state_tracker/st_context.c | 9 ++- > 12 files changed, 136 insertions(+), 46 deletions(-) > > -- > 1.9.0 > > _______________________________________________ > 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
