[Openmp-commits] [openmp] 1e3bbf7 - [OpenMP] Re-use affinity raii class in worker spawning

[Jonathan Peyton via Openmp-commits]

Author: Jonathan Peyton
Date: 2023-07-24T15:58:25-05:00
New Revision: 1e3bbf76a1b7be003f41d4a58f672d311b8577d7

URL: https://github.com/llvm/llvm-project/commit/1e3bbf76a1b7be003f41d4a58f672d311b8577d7
DIFF: https://github.com/llvm/llvm-project/commit/1e3bbf76a1b7be003f41d4a58f672d311b8577d7.diff

LOG: [OpenMP] Re-use affinity raii class in worker spawning

Get rid of explicit mask alloc, getthreadaffinity, set temp affinity,
reset to old affinity, dealloc steps in favor of existing
kmp_affinity_raii_t to push/pop a temporary affinity.

Differential Revision: https://reviews.llvm.org/D154650

Added: 
    

Modified: 
    openmp/runtime/src/kmp.h
    openmp/runtime/src/kmp_affinity.cpp
    openmp/runtime/src/kmp_runtime.cpp

Removed: 
    


################################################################################
diff  --git a/openmp/runtime/src/kmp.h b/openmp/runtime/src/kmp.h
index 3a2e8d64f4b620..641d32357ce873 100644
--- a/openmp/runtime/src/kmp.h
+++ b/openmp/runtime/src/kmp.h
@@ -798,6 +798,31 @@ class KMPAffinity {
 typedef KMPAffinity::Mask kmp_affin_mask_t;
 extern KMPAffinity *__kmp_affinity_dispatch;
 
+class kmp_affinity_raii_t {
+  kmp_affin_mask_t *mask;
+  bool restored;
+
+public:
+  kmp_affinity_raii_t(const kmp_affin_mask_t *new_mask = nullptr)
+      : restored(false) {
+    if (KMP_AFFINITY_CAPABLE()) {
+      KMP_CPU_ALLOC(mask);
+      KMP_ASSERT(mask != NULL);
+      __kmp_get_system_affinity(mask, /*abort_on_error=*/true);
+      if (new_mask)
+        __kmp_set_system_affinity(new_mask, /*abort_on_error=*/true);
+    }
+  }
+  void restore() {
+    if (!restored && KMP_AFFINITY_CAPABLE()) {
+      __kmp_set_system_affinity(mask, /*abort_on_error=*/true);
+      KMP_CPU_FREE(mask);
+    }
+    restored = true;
+  }
+  ~kmp_affinity_raii_t() { restore(); }
+};
+
 // Declare local char buffers with this size for printing debug and info
 // messages, using __kmp_affinity_print_mask().
 #define KMP_AFFIN_MASK_PRINT_LEN 1024

diff  --git a/openmp/runtime/src/kmp_affinity.cpp b/openmp/runtime/src/kmp_affinity.cpp
index eead5bdfb9e4fa..cbb80bf3a8485d 100644
--- a/openmp/runtime/src/kmp_affinity.cpp
+++ b/openmp/runtime/src/kmp_affinity.cpp
@@ -1273,28 +1273,6 @@ bool kmp_topology_t::is_close(int hwt1, int hwt2, int hw_level) const {
 ////////////////////////////////////////////////////////////////////////////////
 
 #if KMP_AFFINITY_SUPPORTED
-class kmp_affinity_raii_t {
-  kmp_affin_mask_t *mask;
-  bool restored;
-
-public:
-  kmp_affinity_raii_t() : restored(false) {
-    KMP_CPU_ALLOC(mask);
-    KMP_ASSERT(mask != NULL);
-    __kmp_get_system_affinity(mask, TRUE);
-  }
-  void restore() {
-    __kmp_set_system_affinity(mask, TRUE);
-    KMP_CPU_FREE(mask);
-    restored = true;
-  }
-  ~kmp_affinity_raii_t() {
-    if (!restored) {
-      __kmp_set_system_affinity(mask, TRUE);
-      KMP_CPU_FREE(mask);
-    }
-  }
-};
 
 bool KMPAffinity::picked_api = false;
 

diff  --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
index 2d5b37b2308b93..38d5470267b8e0 100644
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -4763,25 +4763,6 @@ static void __kmp_initialize_team(kmp_team_t *team, int new_nproc,
   KF_TRACE(10, ("__kmp_initialize_team: exit: team=%p\n", team));
 }
 
-#if (KMP_OS_LINUX || KMP_OS_FREEBSD) && KMP_AFFINITY_SUPPORTED
-/* Sets full mask for thread and returns old mask, no changes to structures. */
-static void
-__kmp_set_thread_affinity_mask_full_tmp(kmp_affin_mask_t *old_mask) {
-  if (KMP_AFFINITY_CAPABLE()) {
-    int status;
-    if (old_mask != NULL) {
-      status = __kmp_get_system_affinity(old_mask, TRUE);
-      int error = errno;
-      if (status != 0) {
-        __kmp_fatal(KMP_MSG(ChangeThreadAffMaskError), KMP_ERR(error),
-                    __kmp_msg_null);
-      }
-    }
-    __kmp_set_system_affinity(__kmp_affin_fullMask, TRUE);
-  }
-}
-#endif
-
 #if KMP_AFFINITY_SUPPORTED
 
 // __kmp_partition_places() is the heart of the OpenMP 4.0 affinity mechanism.
@@ -5347,12 +5328,6 @@ __kmp_allocate_team(kmp_root_t *root, int new_nproc, int max_nproc,
 #endif
       }
     } else { // team->t.t_nproc < new_nproc
-#if (KMP_OS_LINUX || KMP_OS_FREEBSD) && KMP_AFFINITY_SUPPORTED
-      kmp_affin_mask_t *old_mask;
-      if (KMP_AFFINITY_CAPABLE()) {
-        KMP_CPU_ALLOC(old_mask);
-      }
-#endif
 
       KA_TRACE(20,
                ("__kmp_allocate_team: increasing hot team thread count to %d\n",
@@ -5401,7 +5376,7 @@ __kmp_allocate_team(kmp_root_t *root, int new_nproc, int max_nproc,
            primary thread, so if a lot of workers are created on the single
            core quickly, they don't get a chance to set their own affinity for
            a long time. */
-        __kmp_set_thread_affinity_mask_full_tmp(old_mask);
+        kmp_affinity_raii_t new_temp_affinity{__kmp_affin_fullMask};
 #endif
 
         /* allocate new threads for the hot team */
@@ -5432,11 +5407,7 @@ __kmp_allocate_team(kmp_root_t *root, int new_nproc, int max_nproc,
         }
 
 #if (KMP_OS_LINUX || KMP_OS_FREEBSD) && KMP_AFFINITY_SUPPORTED
-        if (KMP_AFFINITY_CAPABLE()) {
-          /* Restore initial primary thread's affinity mask */
-          __kmp_set_system_affinity(old_mask, TRUE);
-          KMP_CPU_FREE(old_mask);
-        }
+        new_temp_affinity.restore();
 #endif
 #if KMP_NESTED_HOT_TEAMS
       } // end of check of t_nproc vs. new_nproc vs. hot_team_nth