Vedran, Just to add a bit more context -- programming a strange viewport causes us to turn off guardband clipping. I haven't measured the impact on dota2, but when it was initially enabled it was a nice win for some other games.
-- Chris On Thu, Oct 31, 2013 at 3:38 AM, Chad Versace <chad.vers...@linux.intel.com> wrote: > On 10/30/2013 06:43 AM, Paul Berry wrote: >> >> On 30 October 2013 00:00, Eric Anholt <e...@anholt.net> wrote: >> >>> One of the things I was wondering about for dota2 performance was >>> whether missing the fast clears was a big performance hit -- >>> particularly with the fips numbers indicating a lot of time spent in >>> clears. However, applying this patch: >>> >>> diff --git a/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp >>> b/src/mesa/drivers/dr >>> index d1933ce..2843ed6 100644 >>> --- a/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp >>> +++ b/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp >>> @@ -156,7 +156,11 @@ is_color_fast_clear_compatible(struct brw_context >>> *brw, >>> if (color->f[i] != 0.0 && color->f[i] != 1.0) { >>> perf_debug("Clear color unsupported by fast color clear. " >>> "Falling back to slow clear.\n"); >>> - return false; >>> + printf("SMASHING FAST CLEAR %f %f %f %f %dx%d\n", >>> + color->f[0], color->f[1], color->f[2], color->f[3], >>> + brw->ctx.DrawBuffer->_Xmax - brw->ctx.DrawBuffer->_Xmin, >>> + brw->ctx.DrawBuffer->_Ymax - >>> brw->ctx.DrawBuffer->_Ymin); >>> + return true; >>> } >>> } >>> return true; >>> >>> produced a lot of output: >>> >>> SMASHING FAST CLEAR 0.501961 0.501961 0.501961 1.000000 1440x900 >>> SMASHING FAST CLEAR 0.901961 0.901961 0.901961 1.000000 64x64 >>> SMASHING FAST CLEAR 0.501961 0.501961 0.501961 1.000000 1440x900 >>> SMASHING FAST CLEAR 0.901961 0.901961 0.901961 1.000000 64x64 >>> >>> but no performance difference: >>> >>> anholt@yvain:/home/anholt% ministat before after >>> x before >>> + after >>> >>> >>> +--------------------------------------------------------------------------+ >>> | x x x + + + + * x >>> +| >>> ||__________________M___A_|_________________AM__|____________| >>> | >>> >>> >>> +--------------------------------------------------------------------------+ >>> N Min Max Median Avg >>> Stddev >>> x 6 13.51 13.64 13.55 13.56 >>> 0.056568542 >>> + 6 13.56 13.68 13.61 13.606667 >>> 0.042739521 >>> No difference proven at 95.0% confidence >>> >>> (test was done with the printf run only a single time) >>> >> >> Hmm, interesting. A few thoughts: >> > >> - Chad told me on Monday about some counterintuitive stuff he was seeing >> where fast clear appeared to be slower than slow clear. I don't recall >> the >> details. > > > Disregard the counterintuitive behavior I observed until further notice. > Last night, Eero informed me that the microbenchmark's javascript was > written badly, which produced false framerate results due to synchronization > issues between Chrome's Webkit process and GPU process. I plan to fix the > javascript issues and re-test. > > > _______________________________________________ > 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