[Openmp-commits] [openmp] 4932101 - [OpenMP] libomp: fix ittnotify stack stitching for teams construct

[via Openmp-commits]

Author: AndreyChurbanov
Date: 2021-02-26T00:23:24+03:00
New Revision: 493210117785c348dcbbf7fc3615020ee81d2c9d

URL: https://github.com/llvm/llvm-project/commit/493210117785c348dcbbf7fc3615020ee81d2c9d
DIFF: https://github.com/llvm/llvm-project/commit/493210117785c348dcbbf7fc3615020ee81d2c9d.diff

LOG: [OpenMP] libomp: fix ittnotify stack stitching for teams construct

Stitching id could be overridden causing reference of destroyed object
when number of teams is 1. The patch separates stitching id store
location for teams and parallel nested in teams.

Differential Revision: https://reviews.llvm.org/D96562

Added: 
    

Modified: 
    openmp/runtime/src/kmp_runtime.cpp

Removed: 
    


################################################################################
diff  --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
index bc39d7d6e689..fa18091c8340 100644
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -1580,6 +1580,7 @@ int __kmp_fork_call(ident_t *loc, int gtid,
         parent_team->t.t_region_time = tmp_time;
       }
       if (__itt_stack_caller_create_ptr) {
+        KMP_DEBUG_ASSERT(parent_team->t.t_stack_id == NULL);
         // create new stack stitching id before entering fork barrier
         parent_team->t.t_stack_id = __kmp_itt_stack_caller_create();
       }
@@ -1619,12 +1620,13 @@ int __kmp_fork_call(ident_t *loc, int gtid,
     }
 #endif
 
+    int enter_teams = 0;
     if (parent_team->t.t_active_level >=
         master_th->th.th_current_task->td_icvs.max_active_levels) {
       nthreads = 1;
     } else {
-      int enter_teams = ((ap == NULL && active_level == 0) ||
-                         (ap && teams_level > 0 && teams_level == level));
+      enter_teams = ((ap == NULL && active_level == 0) ||
+                     (ap && teams_level > 0 && teams_level == level));
       nthreads =
           master_set_numthreads
               ? master_set_numthreads
@@ -2143,9 +2145,18 @@ int __kmp_fork_call(ident_t *loc, int gtid,
 
 #if USE_ITT_BUILD
     if (__itt_stack_caller_create_ptr) {
-      team->t.t_stack_id =
-          __kmp_itt_stack_caller_create(); // create new stack stitching id
-      // before entering fork barrier
+      // create new stack stitching id before entering fork barrier
+      if (!enter_teams) {
+        KMP_DEBUG_ASSERT(team->t.t_stack_id == NULL);
+        team->t.t_stack_id = __kmp_itt_stack_caller_create();
+      } else if (parent_team->t.t_serialized) {
+        // keep stack stitching id in the serialized parent_team;
+        // current team will be used for parallel inside the teams;
+        // if parent_team is active, then it already keeps stack stitching id
+        // for the league of teams
+        KMP_DEBUG_ASSERT(parent_team->t.t_stack_id == NULL);
+        parent_team->t.t_stack_id = __kmp_itt_stack_caller_create();
+      }
     }
 #endif /* USE_ITT_BUILD */
 
@@ -2305,9 +2316,27 @@ void __kmp_join_call(ident_t *loc, int gtid
     // AC: No barrier for internal teams at exit from teams construct.
     //     But there is barrier for external team (league).
     __kmp_internal_join(loc, gtid, team);
+#if USE_ITT_BUILD
+    if (__itt_stack_caller_create_ptr) {
+      KMP_DEBUG_ASSERT(team->t.t_stack_id != NULL);
+      // destroy the stack stitching id after join barrier
+      __kmp_itt_stack_caller_destroy((__itt_caller)team->t.t_stack_id);
+      team->t.t_stack_id = NULL;
+    }
+#endif
   } else {
     master_th->th.th_task_state =
         0; // AC: no tasking in teams (out of any parallel)
+#if USE_ITT_BUILD
+    if (__itt_stack_caller_create_ptr && parent_team->t.t_serialized) {
+      KMP_DEBUG_ASSERT(parent_team->t.t_stack_id != NULL);
+      // destroy the stack stitching id on exit from the teams construct
+      // if parent_team is active, then the id will be destroyed later on
+      // by master of the league of teams
+      __kmp_itt_stack_caller_destroy((__itt_caller)parent_team->t.t_stack_id);
+      parent_team->t.t_stack_id = NULL;
+    }
+#endif
   }
 
   KMP_MB();
@@ -2318,10 +2347,6 @@ void __kmp_join_call(ident_t *loc, int gtid
 #endif
 
 #if USE_ITT_BUILD
-  if (__itt_stack_caller_create_ptr) {
-    // destroy the stack stitching id after join barrier
-    __kmp_itt_stack_caller_destroy((__itt_caller)team->t.t_stack_id);
-  }
   // Mark end of "parallel" region for Intel(R) VTune(TM) analyzer.
   if (team->t.t_active_level == 1 &&
       (!master_th->th.th_teams_microtask || /* not in teams construct */
@@ -7199,9 +7224,14 @@ int __kmp_invoke_task_func(int gtid) {
   __kmp_run_before_invoked_task(gtid, tid, this_thr, team);
 #if USE_ITT_BUILD
   if (__itt_stack_caller_create_ptr) {
-    __kmp_itt_stack_callee_enter(
-        (__itt_caller)
-            team->t.t_stack_id); // inform ittnotify about entering user's code
+    // inform ittnotify about entering user's code
+    if (team->t.t_stack_id != NULL) {
+      __kmp_itt_stack_callee_enter((__itt_caller)team->t.t_stack_id);
+    } else {
+      KMP_DEBUG_ASSERT(team->t.t_parent->t.t_stack_id != NULL);
+      __kmp_itt_stack_callee_enter(
+          (__itt_caller)team->t.t_parent->t.t_stack_id);
+    }
   }
 #endif /* USE_ITT_BUILD */
 #if INCLUDE_SSC_MARKS
@@ -7265,9 +7295,14 @@ int __kmp_invoke_task_func(int gtid) {
 
 #if USE_ITT_BUILD
   if (__itt_stack_caller_create_ptr) {
-    __kmp_itt_stack_callee_leave(
-        (__itt_caller)
-            team->t.t_stack_id); // inform ittnotify about leaving user's code
+    // inform ittnotify about leaving user's code
+    if (team->t.t_stack_id != NULL) {
+      __kmp_itt_stack_callee_leave((__itt_caller)team->t.t_stack_id);
+    } else {
+      KMP_DEBUG_ASSERT(team->t.t_parent->t.t_stack_id != NULL);
+      __kmp_itt_stack_callee_leave(
+          (__itt_caller)team->t.t_parent->t.t_stack_id);
+    }
   }
 #endif /* USE_ITT_BUILD */
   __kmp_run_after_invoked_task(gtid, tid, this_thr, team);