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Backport ppc openmp patch

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Backport patch from https://github.com/llvm/llvm-project/pull/111831
to fix openmp affinity tests on some brew ppc runners.

Related: RHEL-57454
This commit is contained in:
Nikita Popov 2024-10-10 15:23:07 +02:00
parent fac49312cf
commit 7b2f59cfc4
2 changed files with 205 additions and 3 deletions
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198
0001-openmp-Use-core_siblings_list-if-physical_package_id.patch Normal file
View File

@ -0,0 +1,198 @@
From c4cedb269c5dd82bb5d1c7a3cd24b74b1c8ea1f7 Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov@redhat.com>
Date: Thu, 10 Oct 2024 12:47:33 +0000
Subject: [PATCH] [openmp] Use core_siblings_list if physical_package_id not
available
On powerpc, physical_package_id may not be available. Currently,
this causes openmp to fall back to flat topology and various
affinity tests fail.
Fix this by parsing core_siblings_list to deterimine which cpus
belong to the same socket. This matches what the testing code
does. The code to parse the CPU list format thankfully already
exists.
Fixes https://github.com/llvm/llvm-project/issues/111809.
---
openmp/runtime/src/kmp_affinity.cpp | 93 ++++++++++++++------
openmp/runtime/test/affinity/kmp-hw-subset.c | 2 +-
2 files changed, 65 insertions(+), 30 deletions(-)
diff --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
index cf5cad04eb57..d4de84381217 100644
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -1589,15 +1589,13 @@ kmp_str_buf_t *__kmp_affinity_str_buf_mask(kmp_str_buf_t *buf,
return buf;
}
-// Return (possibly empty) affinity mask representing the offline CPUs
-// Caller must free the mask
-kmp_affin_mask_t *__kmp_affinity_get_offline_cpus() {
- kmp_affin_mask_t *offline;
- KMP_CPU_ALLOC(offline);
- KMP_CPU_ZERO(offline);
+static kmp_affin_mask_t *__kmp_parse_cpu_list(const char *path) {
+ kmp_affin_mask_t *mask;
+ KMP_CPU_ALLOC(mask);
+ KMP_CPU_ZERO(mask);
#if KMP_OS_LINUX
int n, begin_cpu, end_cpu;
- kmp_safe_raii_file_t offline_file;
+ kmp_safe_raii_file_t file;
auto skip_ws = [](FILE *f) {
int c;
do {
@@ -1606,29 +1604,29 @@ kmp_affin_mask_t *__kmp_affinity_get_offline_cpus() {
if (c != EOF)
ungetc(c, f);
};
- // File contains CSV of integer ranges representing the offline CPUs
+ // File contains CSV of integer ranges representing the CPUs
// e.g., 1,2,4-7,9,11-15
- int status = offline_file.try_open("/sys/devices/system/cpu/offline", "r");
+ int status = file.try_open(path, "r");
if (status != 0)
- return offline;
- while (!feof(offline_file)) {
- skip_ws(offline_file);
- n = fscanf(offline_file, "%d", &begin_cpu);
+ return mask;
+ while (!feof(file)) {
+ skip_ws(file);
+ n = fscanf(file, "%d", &begin_cpu);
if (n != 1)
break;
- skip_ws(offline_file);
- int c = fgetc(offline_file);
+ skip_ws(file);
+ int c = fgetc(file);
if (c == EOF || c == ',') {
// Just single CPU
end_cpu = begin_cpu;
} else if (c == '-') {
// Range of CPUs
- skip_ws(offline_file);
- n = fscanf(offline_file, "%d", &end_cpu);
+ skip_ws(file);
+ n = fscanf(file, "%d", &end_cpu);
if (n != 1)
break;
- skip_ws(offline_file);
- c = fgetc(offline_file); // skip ','
+ skip_ws(file);
+ c = fgetc(file); // skip ','
} else {
// Syntax problem
break;
@@ -1638,13 +1636,19 @@ kmp_affin_mask_t *__kmp_affinity_get_offline_cpus() {
end_cpu >= __kmp_xproc || begin_cpu > end_cpu) {
continue;
}
- // Insert [begin_cpu, end_cpu] into offline mask
+ // Insert [begin_cpu, end_cpu] into mask
for (int cpu = begin_cpu; cpu <= end_cpu; ++cpu) {
- KMP_CPU_SET(cpu, offline);
+ KMP_CPU_SET(cpu, mask);
}
}
#endif
- return offline;
+ return mask;
+}
+
+// Return (possibly empty) affinity mask representing the offline CPUs
+// Caller must free the mask
+kmp_affin_mask_t *__kmp_affinity_get_offline_cpus() {
+ return __kmp_parse_cpu_list("/sys/devices/system/cpu/offline");
}
// Return the number of available procs
@@ -3175,6 +3179,30 @@ static inline const char *__kmp_cpuinfo_get_envvar() {
return envvar;
}
+static bool __kmp_package_id_from_core_sibling_list(unsigned **threadInfo,
+ unsigned idx) {
+ char path[256];
+ KMP_SNPRINTF(path, sizeof(path),
+ "/sys/devices/system/cpu/cpu%u/topology/core_siblings_list",
+ threadInfo[idx][osIdIndex]);
+ kmp_affin_mask_t *siblings = __kmp_parse_cpu_list(path);
+ for (unsigned i = 0; i < __kmp_xproc; ++i) {
+ if (!KMP_CPU_ISSET(i, siblings))
+ continue;
+ if (threadInfo[i][pkgIdIndex] == UINT_MAX) {
+ // Arbitrarily pick the first index we encounter, it only matters that
+ // the value is the same for all siblings.
+ threadInfo[i][pkgIdIndex] = idx;
+ } else if (threadInfo[i][pkgIdIndex] != idx) {
+ // Contradictory sibling lists.
+ KMP_CPU_FREE(siblings);
+ return false;
+ }
+ }
+ KMP_CPU_FREE(siblings);
+ return true;
+}
+
// Parse /proc/cpuinfo (or an alternate file in the same format) to obtain the
// affinity map. On AIX, the map is obtained through system SRAD (Scheduler
// Resource Allocation Domain).
@@ -3550,18 +3578,13 @@ static bool __kmp_affinity_create_cpuinfo_map(int *line,
return false;
}
- // Check for missing fields. The osId field must be there, and we
- // currently require that the physical id field is specified, also.
+ // Check for missing fields. The osId field must be there. The physical
+ // id field will be checked later.
if (threadInfo[num_avail][osIdIndex] == UINT_MAX) {
CLEANUP_THREAD_INFO;
*msg_id = kmp_i18n_str_MissingProcField;
return false;
}
- if (threadInfo[0][pkgIdIndex] == UINT_MAX) {
- CLEANUP_THREAD_INFO;
- *msg_id = kmp_i18n_str_MissingPhysicalIDField;
- return false;
- }
// Skip this proc if it is not included in the machine model.
if (KMP_AFFINITY_CAPABLE() &&
@@ -3591,6 +3614,18 @@ static bool __kmp_affinity_create_cpuinfo_map(int *line,
}
*line = 0;
+ // At least on powerpc, Linux may return -1 for physical_package_id. Try
+ // to reconstruct topology from core_sibling_list in that case.
+ for (i = 0; i < num_avail; ++i) {
+ if (threadInfo[i][pkgIdIndex] == UINT_MAX) {
+ if (!__kmp_package_id_from_core_sibling_list(threadInfo, i)) {
+ CLEANUP_THREAD_INFO;
+ *msg_id = kmp_i18n_str_MissingPhysicalIDField;
+ return false;
+ }
+ }
+ }
+
#if KMP_MIC && REDUCE_TEAM_SIZE
unsigned teamSize = 0;
#endif // KMP_MIC && REDUCE_TEAM_SIZE
diff --git a/openmp/runtime/test/affinity/kmp-hw-subset.c b/openmp/runtime/test/affinity/kmp-hw-subset.c
index 606fcdfbada9..0b49969bd3b1 100644
--- a/openmp/runtime/test/affinity/kmp-hw-subset.c
+++ b/openmp/runtime/test/affinity/kmp-hw-subset.c
@@ -25,7 +25,7 @@ static int compare_hw_subset_places(const place_list_t *openmp_places,
expected_per_place = nthreads_per_core;
} else {
expected_total = nsockets;
- expected_per_place = ncores_per_socket;
+ expected_per_place = ncores_per_socket * nthreads_per_core;
}
if (openmp_places->num_places != expected_total) {
fprintf(stderr, "error: KMP_HW_SUBSET did not half each resource layer!\n");
--
2.46.0

10
llvm.spec
View File

@ -177,7 +177,7 @@
#region main package
Name: %{pkg_name_llvm}
Version: %{maj_ver}.%{min_ver}.%{patch_ver}%{?rc_ver:~rc%{rc_ver}}%{?llvm_snapshot_version_suffix:~%{llvm_snapshot_version_suffix}}
Release: 2%{?dist}
Release: 3%{?dist}
Summary: The Low Level Virtual Machine
License: Apache-2.0 WITH LLVM-exception OR NCSA
@ -206,11 +206,12 @@ Source3001: https://github.com/llvm/llvm-project/releases/download/llvmorg-%{com
Source1000: version.spec.inc
%endif
#region LLVM patches
#region OpenMP patches
%if %{maj_ver} < 20
Patch1001: 0001-openmp-Add-option-to-disable-tsan-tests-111548.patch
Patch1002: 0001-openmp-Use-core_siblings_list-if-physical_package_id.patch
%endif
#endregion
#endregion OpenMP patches
#region CLANG patches
Patch2001: 0001-PATCH-clang-Make-funwind-tables-the-default-on-all-a.patch
@ -2370,6 +2371,9 @@ fi
#region changelog
%changelog
* Thu Oct 10 2024 Nikita Popov <npopov@redhat.com> - 19.1.1-3
- Backport ppc openmp patch
* Wed Oct 09 2024 Nikita Popov <npopov@redhat.com> - 19.1.1-2
- Fix build on some brew builders