commit 3625bdbad9fd57d1cdb1e5615854545167d4adcb
Author: Anthony Castaldo <TonyCastaldo@icl.utk.edu>
Date:   Wed Aug 26 17:18:29 2020 -0400

    This modifies PAPI_library_init() to initialize components in two classes,
    separated by the initialization of the papi thread structure.  The first class
    is those that need no thread structure, currently everything but perf_event and
    perf_event_uncore. Following the init of the threading structure, we init the
    second class (perf_event and perf_event_uncore) that DOES need the thread
    structure to successfully init_component().  This required a change to
    _papi_hwi_init_global(), to add an argument to distinguish which class it
    should initialize.

diff --git a/src/papi.c b/src/papi.c
index 33cc29935..ed75af493 100644
--- a/src/papi.c
+++ b/src/papi.c
@@ -1151,7 +1151,23 @@ PAPI_library_init( int version )
 	   papi_return( init_retval );
 	}
 
-	/* Initialize thread globals, including the main threads  */
+	/* Initialize component globals EXCEPT for perf_event, perf_event_uncore.
+    * To avoid race conditions, these components use the thread local storage
+    * construct initialized by _papi_hwi_init_global_threads(), from within 
+    * their init_component(). So these must have init_component() run AFTER
+    * _papi_hwi_init_global_threads. Other components demand that init threads
+    * run AFTER init_component(), which sets up globals they need.
+    */
+
+	tmp = _papi_hwi_init_global( 0 ); /* Selector 0 to skip perf_event, perf_event_uncore */
+	if ( tmp ) {
+		init_retval = tmp;
+		_papi_hwi_shutdown_global_internal(  );
+		_in_papi_library_init_cnt--;
+		papi_return( init_retval );
+	}
+	
+   /* Initialize thread globals, including the main threads  */
 
 	tmp = _papi_hwi_init_global_threads(  );
 	if ( tmp ) {
@@ -1161,9 +1177,9 @@ PAPI_library_init( int version )
 		papi_return( init_retval );
 	}
 
-	/* Initialize component globals */
+	/* Initialize perf_event, perf_event_uncore components */
 
-	tmp = _papi_hwi_init_global(  );
+	tmp = _papi_hwi_init_global( 1 ); /* Selector 1 for only perf_event, perf_event_uncore */
 	if ( tmp ) {
 		init_retval = tmp;
 		_papi_hwi_shutdown_global_internal(  );
diff --git a/src/papi_internal.c b/src/papi_internal.c
index 5a1ccd433..e6dd319c2 100644
--- a/src/papi_internal.c
+++ b/src/papi_internal.c
@@ -1928,11 +1928,13 @@ int papi_num_components = ( sizeof ( _papi_hwd ) / sizeof ( *_papi_hwd ) ) - 1;
  * Routine that initializes all available components.
  * A component is available if a pointer to its info vector
  * appears in the NULL terminated_papi_hwd table.
+ * Modified to accept an arg: 0=do not init perf_event or 
+ * perf_event_uncore. 1=init ONLY perf_event or perf_event_uncore.
  */
 int
-_papi_hwi_init_global( void )
+_papi_hwi_init_global( int PE_OR_PEU )
 {
-        int retval, i = 0;
+        int retval, is_pe_peu, i = 0;
 
 	retval = _papi_hwi_innoculate_os_vector( &_papi_os_vector );
 	if ( retval != PAPI_OK ) {
@@ -1940,14 +1942,16 @@ _papi_hwi_init_global( void )
 	}
 
 	while ( _papi_hwd[i] ) {
-
+      is_pe_peu = 0;
+      if (strcmp(_papi_hwd[i]->cmp_info.name, "perf_event") == 0) is_pe_peu=1;
+      if (strcmp(_papi_hwd[i]->cmp_info.name, "perf_event_uncore") == 0) is_pe_peu=1;
 	   retval = _papi_hwi_innoculate_vector( _papi_hwd[i] );
 	   if ( retval != PAPI_OK ) {
 	      return retval;
 	   }
 
 	   /* We can be disabled by user before init */
-	   if (!_papi_hwd[i]->cmp_info.disabled) {
+	   if (!_papi_hwd[i]->cmp_info.disabled && (PE_OR_PEU == is_pe_peu)) {
 	      retval = _papi_hwd[i]->init_component( i );
 	      _papi_hwd[i]->cmp_info.disabled=retval;
 
diff --git a/src/papi_internal.h b/src/papi_internal.h
index 6492fea4e..e0f5acd74 100644
--- a/src/papi_internal.h
+++ b/src/papi_internal.h
@@ -467,7 +467,7 @@ int _papi_hwi_read( hwd_context_t * context, EventSetInfo_t * ESI,
 		    long long *values );
 int _papi_hwi_cleanup_eventset( EventSetInfo_t * ESI );
 int _papi_hwi_convert_eventset_to_multiplex( _papi_int_multiplex_t * mpx );
-int _papi_hwi_init_global( void );
+int _papi_hwi_init_global( int PE_OR_PEU );
 int _papi_hwi_init_global_internal( void );
 int _papi_hwi_init_os(void);
 void _papi_hwi_init_errors(void);