On 2016-06-10 13:05:16, Kenneth Graunke wrote: > Curro figured this out by investigating the simulator. Apparently > there's also a workaround in the Windows driver. I'm not sure it's > actually documented anywhere. > > We were underallocating the scratch buffer by a factor of 128/70. > > Cc: "12.0" <mesa-sta...@lists.freedesktop.org> > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> > --- > src/mesa/drivers/dri/i965/brw_cs.c | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/src/mesa/drivers/dri/i965/brw_cs.c > b/src/mesa/drivers/dri/i965/brw_cs.c > index c8598d6..329adff 100644 > --- a/src/mesa/drivers/dri/i965/brw_cs.c > +++ b/src/mesa/drivers/dri/i965/brw_cs.c > @@ -150,9 +150,28 @@ brw_codegen_cs_prog(struct brw_context *brw, > > if (prog_data.base.total_scratch) { > const unsigned subslices = MAX2(brw->intelScreen->subslice_total, 1); > + > + /* WaCSScratchSize:hsw > + * > + * Haswell's scratch space address calculation appears to be sparse > + * rather than tightly packed. The Thread ID has bits indicating > + * which subslice, EU within a subslice, and thread within an EU > + * it is. There's a maximum of two slices and two subslices, so these > + * can be stored with a single bit. Even though there are only 10 EUs > + * per subslice, this is stored in 4 bits, so there's an effective > + * maximum value of 16 EUs. Similarly, although there are only 7 > + * threads per EU, this is stored in a 3 bit number, giving an > effective > + * maximum value of 8 threads per EU. > + * > + * This means that we need to use 16 * 8 instead of 10 * 7 for the > + * number of threads per subslice. > + */ > + const unsigned threads_per_subslice =
How about naming the variable something like scratch_ids_per_subslice? -Jordan > + brw->is_haswell ? 16 * 8 : brw->max_cs_threads; > + > brw_get_scratch_bo(brw, &brw->cs.base.scratch_bo, > prog_data.base.total_scratch * > - brw->max_cs_threads * subslices); > + threads_per_subslice * subslices); > } > > if (unlikely(INTEL_DEBUG & DEBUG_CS)) > -- > 2.8.3 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev