HI all, Sorry, just ignore this patch with incorrect subject. I will send correct one shortly.
Regards, Andrii. On Thu, Jun 21, 2018 at 4:12 PM, Andrii Simiklit <asimiklit.w...@gmail.com> wrote: > We can not use the VUE Dereference flags combination for EOT > message under ILK and SNB because the threads are not initialized > there with initial VUE handle unlike Pre-IL. > So to avoid GPU hangs on SNB and ILK we need > to avoid usage of the VUE Dereference flags combination. > (Was tested only on SNB but according to the specification > SNB Volume 2 Part 1: 1.6.5.3, 1.6.5.6 > the ILK must behave itself in the similar way) > > v2: Approach to fix this issue was changed. > Instead of different EOT flags in the program end > we will create VUE every time even if GS produces no output. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105399 > > Signed-off-by: Andrii Simiklit <andrii.simik...@globallogic.com> > --- > src/intel/compiler/gen6_gs_visitor.cpp | 88 > +++++++++------------------------- > 1 file changed, 23 insertions(+), 65 deletions(-) > > diff --git a/src/intel/compiler/gen6_gs_visitor.cpp > b/src/intel/compiler/gen6_gs_visitor.cpp > index ac3ba55..b831d33 100644 > --- a/src/intel/compiler/gen6_gs_visitor.cpp > +++ b/src/intel/compiler/gen6_gs_visitor.cpp > @@ -300,11 +300,10 @@ gen6_gs_visitor::emit_urb_write_opcode(bool > complete, int base_mrf, > /* Otherwise we always request to allocate a new VUE handle. If > this is > * the last write before the EOT message and the new handle never > gets > * used it will be dereferenced when we send the EOT message. This > is > - * necessary to avoid different setups (under Pre-IL only) for the > EOT message (one for the > + * necessary to avoid different setups for the EOT message (one for > the > * case when there is no output and another for the case when there > is) > * which would require to end the program with an IF/ELSE/ENDIF > block, > - * something we do not want. > - * But for ILK and SNB we can not avoid the end the program with an > IF/ELSE/ENDIF block. > + * something we do not want. > */ > inst = emit(GS_OPCODE_URB_WRITE_ALLOCATE); > inst->urb_write_flags = BRW_URB_WRITE_COMPLETE; > @@ -351,27 +350,27 @@ gen6_gs_visitor::emit_thread_end() > int max_usable_mrf = FIRST_SPILL_MRF(devinfo->gen); > > /* Issue the FF_SYNC message and obtain the initial VUE handle. */ > - emit(CMP(dst_null_ud(), this->vertex_count, brw_imm_ud(0u), > BRW_CONDITIONAL_G)); > - emit(IF(BRW_PREDICATE_NORMAL)); > - { > - this->current_annotation = "gen6 thread end: ff_sync"; > + this->current_annotation = "gen6 thread end: ff_sync"; > > - vec4_instruction *inst; > - if (prog->info.has_transform_feedback_varyings) { > + vec4_instruction *inst = NULL; > + if (prog->info.has_transform_feedback_varyings) { > src_reg sol_temp(this, glsl_type::uvec4_type); > emit(GS_OPCODE_FF_SYNC_SET_PRIMITIVES, > - dst_reg(this->svbi), > - this->vertex_count, > - this->prim_count, > - sol_temp); > + dst_reg(this->svbi), > + this->vertex_count, > + this->prim_count, > + sol_temp); > inst = emit(GS_OPCODE_FF_SYNC, > dst_reg(this->temp), this->prim_count, this->svbi); > - } else { > + } else { > inst = emit(GS_OPCODE_FF_SYNC, > dst_reg(this->temp), this->prim_count, > brw_imm_ud(0u)); > - } > - inst->base_mrf = base_mrf; > + } > + inst->base_mrf = base_mrf; > > + emit(CMP(dst_null_ud(), this->vertex_count, brw_imm_ud(0u), > BRW_CONDITIONAL_G)); > + emit(IF(BRW_PREDICATE_NORMAL)); > + { > /* Loop over all buffered vertices and emit URB write messages */ > this->current_annotation = "gen6 thread end: urb writes init"; > src_reg vertex(this, glsl_type::uint_type); > @@ -415,7 +414,7 @@ gen6_gs_visitor::emit_thread_end() > dst_reg reg = dst_reg(MRF, mrf); > reg.type = output_reg[varying][0].type; > data.type = reg.type; > - vec4_instruction *inst = emit(MOV(reg, data)); > + inst = emit(MOV(reg, data)); > inst->force_writemask_all = true; > > mrf++; > @@ -450,11 +449,8 @@ gen6_gs_visitor::emit_thread_end() > if (prog->info.has_transform_feedback_varyings) > xfb_write(); > } > - const bool common_eot_approach_can_be_used = (devinfo->gen < 5); > - if(common_eot_approach_can_be_used) > - { > - emit(BRW_OPCODE_ENDIF); > - } > + emit(BRW_OPCODE_ENDIF); > + > /* Finally, emit EOT message. > * > * In gen6 we need to end the thread differently depending on whether > we have > @@ -464,35 +460,11 @@ gen6_gs_visitor::emit_thread_end() > * > * However, this would lead us to end the program with an ENDIF opcode, > * which we want to avoid, so what we do is that we always request a > new > - * VUE handle every time we do a URB WRITE, even for the last vertex > we emit. > + * VUE handle every time, even if GS produces no output. > * With this we make sure that whether we have emitted at least one > vertex > * or none at all, we have to finish the thread without writing to the > URB, > - * which works for both cases (but only under Pre-IL) by setting > - * the COMPLETE and UNUSED flags in the EOT message. > - * > - * But under ILK or SNB we must not use combination COMPLETE and > UNUSED > - * because this combination could be used only for already allocated > VUE. > - * But unlike Pre-IL in the ILK and SNB > - * the initial VUE is not passed to threads. > - * This behaver mentioned in specification: > - * SNB Volume 2 Part 1: > - * "1.6.5.3 VUE Allocation (GS, CLIP) [DevIL]" > - * "1.6.5.4 VUE Allocation (GS) [DevSNB+]" > - * "The threads are not passed an initial handle. > - * Instead, they request a first handle (if any) > - * via the URB shared function’s FF_SYNC message (see Shared > Functions). > - * If additional handles are required, > - * the URB_WRITE allocate mechanism (mentioned above) is used." > - * > - * So for ILK and for SNB we must use only UNUSED flag. > - * This is accepteble combination according to: > - * SNB Volume 4 Part 2: > - * "2.4.2 Message Descriptor" > - * "Table lists the valid and invalid combinations of > - * the Complete, Used, Allocate and EOT bits" > - * "Thread terminate non-write of URB" > - * SNB Volume 2 Part 1: > - * "1.6.5.6 Thread Termination" > + * which works for both cases by setting the COMPLETE and UNUSED flags > in > + * the EOT message. > */ > this->current_annotation = "gen6 thread end: EOT"; > > @@ -504,26 +476,12 @@ gen6_gs_visitor::emit_thread_end() > emit(GS_OPCODE_SET_DWORD_2, dst_reg(MRF, base_mrf), data); > } > > - vec4_instruction *inst = emit(GS_OPCODE_THREAD_END); > + inst = emit(GS_OPCODE_THREAD_END); > inst->urb_write_flags = BRW_URB_WRITE_COMPLETE | BRW_URB_WRITE_UNUSED; > inst->base_mrf = base_mrf; > inst->mlen = 1; > - > - if(!common_eot_approach_can_be_used) > - { > - emit(BRW_OPCODE_ELSE); > - > - this->current_annotation = "gen6 thread end: EOT"; > - > - vec4_instruction *unused_urb_inst = emit(GS_OPCODE_THREAD_END); > - unused_urb_inst->urb_write_flags = BRW_URB_WRITE_UNUSED; > - unused_urb_inst->base_mrf = base_mrf; > - unused_urb_inst->mlen = 1; > - > - emit(BRW_OPCODE_ENDIF); > - } > } > - > + > void > gen6_gs_visitor::setup_payload() > { > -- > 2.7.4 > >
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