On Wed, Feb 7, 2018 at 11:55 AM, Francisco Jerez <curroje...@riseup.net> wrote:
> Anuj Phogat <anuj.pho...@gmail.com> writes: > > > On Wed, Feb 7, 2018 at 11:14 AM, Kenneth Graunke <kenn...@whitecape.org> > > wrote: > > > >> On Tuesday, February 6, 2018 5:09:10 PM PST Anuj Phogat wrote: > >> > From Message Descriptor section in gfxspecs: > >> > "Memory fence messages without Commit Enable set do not return > >> > anything to the thread (response length is 0 and destination > >> > register is null)." > >> > > >> > It fixes a piglit GPU hang in simulation environment. > >> > Piglit test: arb_shader_image_load_store-shader-mem-barrier > >> > > >> > Signed-off-by: Anuj Phogat <anuj.pho...@gmail.com> > >> > Cc: mesa-sta...@lists.freedesktop.org > >> > --- > >> > src/intel/compiler/brw_eu_emit.c | 8 +++++++- > >> > 1 file changed, 7 insertions(+), 1 deletion(-) > >> > > >> > diff --git a/src/intel/compiler/brw_eu_emit.c > >> b/src/intel/compiler/brw_eu_emit.c > >> > index 1fb9aab51c..c66b813af8 100644 > >> > --- a/src/intel/compiler/brw_eu_emit.c > >> > +++ b/src/intel/compiler/brw_eu_emit.c > >> > @@ -3290,7 +3290,13 @@ brw_memory_fence(struct brw_codegen *p, > >> > */ > >> > insn = next_insn(p, BRW_OPCODE_SEND); > >> > dst = retype(dst, BRW_REGISTER_TYPE_UW); > >> > - brw_set_dest(p, insn, dst); > >> > + > >> > + /* From Message Descriptor section in gfxspecs: > >> > + "Memory fence messages without Commit Enable set do not > return > >> > + anything to the thread (response length is 0 and destination > >> > + register is null). > >> > + */ > >> > + brw_set_dest(p, insn, retype(vec1(brw_null_reg()), > >> BRW_REGISTER_TYPE_UW)); > >> > brw_set_src0(p, insn, dst); > >> > brw_set_memory_fence_message(p, insn, > GEN7_SFID_DATAPORT_DATA_CACHE, > >> > commit_enable); > >> > > >> > >> This seems wrong - it looks like you're doing this for messages with > >> commit enable set, which do return things... > >> > >> Right. I've to check for commit_enable to use null or non-null > destination > > here. I'll send out a v2. > > > > > > You can also just drop the patch, unless you want to change the > front-end in addition to stop allocating a destination for memory fences > on HSW-SKL in order to save a small amount of register pressure? > It also fixes a fulsim error other than reducing register pressure. I'll look in to how to stop allocating dst register for memory fences and send out a v2. Thanks for the suggestion. > > > > >> Cc'ing Curro. > >> >
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
