| Message ID | 87levrsqno.fsf@dem-tschwing-1.ger.mentorg.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix up 'libgomp.oacc-fortran/print-1.f90' GCN offloading compilation [PR104717] (was: [PATCH] fortran: Fix up gfc_trans_oacc_construct [PR104717]) | expand |
Hi! On 2022-04-26T19:25:31+0200, I wrote: > On 2022-04-25T23:19:26+0200, I wrote: >> On 2022-04-20T19:06:17+0200, Jakub Jelinek <jakub@redhat.com> wrote: >>> So that move_sese_region_to_fn works properly, OpenMP/OpenACC constructs >>> for which that function is invoked need an extra artificial BIND_EXPR >>> around their body so that we move all variables of the bodies. >>> >>> The C/C++ FEs do that both for OpenMP constructs like OMP_PARALLEL, OMP_TASK >>> or OMP_TARGET and for OpenACC constructs that behave similarly to >>> OMP_TARGET, but the Fortran FE only does that for OpenMP constructs. >>> >>> The following patch does that for OpenACC constructs too. >>> This fixes ICE on the attached testcase. >> >> ACK, thanks. > >>> Unfortunately, it also regresses >>> FAIL: gfortran.dg/goacc/privatization-1-compute-loop.f90 -O (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -O0 (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -O1 (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -O2 (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -O3 -g (test for excess errors) >>> FAIL: libgomp.oacc-fortran/privatized-ref-2.f90 -DACC_DEVICE_TYPE_host=1 -DACC_MEM_SHARED=1 -foffload=disable -Os (test for excess errors) >>> Those emits emit tons of various messages and now there are some extra ones, >> >> I've fixed these up. > > One more issue became apparent, where the code changes pushed actually do > lead to a GCN offloading compilation failure: > > [...]/libgomp.oacc-fortran/print-1.f90: In function ‘MAIN__._omp_fn.0’: > [...]/libgomp.oacc-fortran/print-1.f90:13:14: error: 512 bytes of gang-private data-share memory exhausted (increase with ‘-mgang-private-size=560’, for example) > 13 | !$acc parallel > | ^ > > In my configuration, I may indeed fix GCN offloading compilation with > '-foffload-options=amdgcn-amdhsa=-mgang-private-size=560', but I don't > think that's generally correct/sufficient, so in the the attached > "Fix up 'libgomp.oacc-fortran/print-1.f90' GCN offloading compilation > [PR104717]", I instead "raise '-mgang-private-size' to an arbitrary high > value". This avoids having to route the actual 'sizeof' from GCC build > down to the test suite harness (which ought to be doable, but > non-trivial). OK to push that: > > +! For GCN offloading compilation, when gang-privatizing 'dt_parm.N' > +! (see below), we run into an 'gang-private data-share memory exhausted' > +! error: the default '-mgang-private-size' is too small. Per > +! 'gcc/fortran/trans-io.cc'/'libgfortran/io/io.h', that one is > +! 'struct st_parameter_dt', which indeed is rather big. Instead of > +! working out its exact size (which may vary per GCC configuration), > +! raise '-mgang-private-size' to an arbitrary high value. > +! { dg-additional-options "-foffload-options=amdgcn-amdhsa=-mgang-private-size=13579" { target openacc_radeon_accel_selected } } > > ... to master branch? (This doubles the use/testing of the > '-mgang-private-size' option!) ;-) Eh. That only works with the default GCN multilib '-march=fiji', testing on gfx803 amdfury2 system. For all of '-march=gfx900' (amdnano2), '-march=gfx906' (amd_ryzen3), '-march=gfx908' (amd-instinct1), I get: libgomp: GCN fatal error: Asynchronous queue error Runtime message: HSA_STATUS_ERROR_MEMORY_APERTURE_VIOLATION: The agent attempted to access memory beyond the largest legal address. ..., and I still get that if lowering the allocation to the minimum, '-foffload-options=amdgcn-amdhsa=-mgang-private-size=560'. This is a really simple OpenACC 'parallel' construct: !$acc parallel write (0, '("The answer is ", I2)') var !$acc end parallel ..., which ought to launch a 1-gang x 1-worker x 1-vector GPU kernel, so I'd assume '-mgang-private-size=560' (or '-mgang-private-size=13579' in fact) is not a problem? Help? Grüße Thomas > We've currently not been doing OpenACC privatization scanning in > 'libgomp.oacc-fortran/print-1.f90', which I've now added, to help > document the issue; no need to review that. > > Of course, the issue could alternatively be fixed by adding more logic to > the GCN back end to auto-scale the allocation, or be fixed by adding more > logic to the compiler to avoid gang-privatizing varibales such as > 'dt_parm.N' in such cases, but that's not something I'm going to look > into at this point. > > Or, of course, be avoided by re-writing the test case to not require > gang-privatizing 'dt_parm.N', but the test case is correct as it is. > > > Grüße > Thomas > > >> PR fortran/104717 >> gcc/fortran/ >> * trans-openmp.cc (gfc_trans_oacc_construct): Wrap construct body >> in an extra BIND_EXPR. > >> --- a/gcc/fortran/trans-openmp.cc >> +++ b/gcc/fortran/trans-openmp.cc >> @@ -4444,7 +4444,9 @@ gfc_trans_oacc_construct (gfc_code *code) >> gfc_start_block (&block); >> oacc_clauses = gfc_trans_omp_clauses (&block, code->ext.omp_clauses, >> code->loc, false, true); >> + pushlevel (); >> stmt = gfc_trans_omp_code (code->block->next, true); >> + stmt = build3_v (BIND_EXPR, NULL, stmt, poplevel (1, 0)); >> stmt = build2_loc (gfc_get_location (&code->loc), construct_code, >> void_type_node, stmt, oacc_clauses); >> gfc_add_expr_to_block (&block, stmt); ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
From 3dfea06371aa9bcc84ad75a2bc821a45e131dca6 Mon Sep 17 00:00:00 2001 From: Thomas Schwinge <thomas@codesourcery.com> Date: Tue, 26 Apr 2022 18:41:23 +0200 Subject: [PATCH] Fix up 'libgomp.oacc-fortran/print-1.f90' GCN offloading compilation [PR104717] That got broken by recent commit b2202431910e30d8505c94d1cb9341cac7080d10 "fortran: Fix up gfc_trans_oacc_construct [PR104717]". PR fortran/104717 libgomp/ * testsuite/libgomp.oacc-fortran/print-1.f90: Add OpenACC privatization scanning. For GCN offloading compilation, raise '-mgang-private-size'. --- .../libgomp.oacc-fortran/print-1.f90 | 30 ++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 index 7b7f73741fe..42a8538e1fb 100644 --- a/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 +++ b/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 @@ -6,11 +6,39 @@ ! Separate file 'print-1-nvptx.f90' for nvptx offloading. ! { dg-skip-if "separate file" { offload_target_nvptx } } +! For GCN offloading compilation, when gang-privatizing 'dt_parm.N' +! (see below), we run into an 'gang-private data-share memory exhausted' +! error: the default '-mgang-private-size' is too small. Per +! 'gcc/fortran/trans-io.cc'/'libgfortran/io/io.h', that one is +! 'struct st_parameter_dt', which indeed is rather big. Instead of +! working out its exact size (which may vary per GCC configuration), +! raise '-mgang-private-size' to an arbitrary high value. +! { dg-additional-options "-foffload-options=amdgcn-amdhsa=-mgang-private-size=13579" { target openacc_radeon_accel_selected } } + +! { dg-additional-options "-fopt-info-note-omp" } +! { dg-additional-options "-foffload=-fopt-info-note-omp" } + +! { dg-additional-options "--param=openacc-privatization=noisy" } +! { dg-additional-options "-foffload=--param=openacc-privatization=noisy" } +! Prune a few: uninteresting, and potentially varying depending on GCC configuration (data types): +! { dg-prune-output {note: variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} } */ + +! It's only with Tcl 8.5 (released in 2007) that "the variable 'varName' +! passed to 'incr' may be unset, and in that case, it will be set to [...]", +! so to maintain compatibility with earlier Tcl releases, we manually +! initialize counter variables: +! { dg-line l_dummy[variable c_compute 0] } +! { dg-message dummy {} { target iN-VAl-Id } l_dummy } to avoid +! "WARNING: dg-line var l_dummy defined, but not used". + program main implicit none integer :: var = 42 -!$acc parallel +!$acc parallel ! { dg-line l_compute[incr c_compute] } + ! { dg-note {variable 'dt_parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} {} { target *-*-* } l_compute$c_compute } + ! { dg-note {variable 'dt_parm\.[0-9]+' ought to be adjusted for OpenACC privatization level: 'gang'} {} { target *-*-* } l_compute$c_compute } + ! { dg-note {variable 'dt_parm\.[0-9]+' adjusted for OpenACC privatization level: 'gang'} {} { target { ! openacc_host_selected } } l_compute$c_compute } write (0, '("The answer is ", I2)') var !$acc end parallel -- 2.25.1