[Openmp-commits] [openmp] r272698 - Fix large overhead with itt notifications on region/barrier name composing

[Jonathan Peyton via Openmp-commits]

Author: jlpeyton
Date: Tue Jun 14 14:27:22 2016
New Revision: 272698

URL: http://llvm.org/viewvc/llvm-project?rev=272698&view=rev
Log:
Fix large overhead with itt notifications on region/barrier name composing

Currently, there is a big overhead in reporting of loop metadata through
ittnotify.  The pair of functions: __kmp_str_loc_init/__kmp_str_loc_free are
replaced with strchr/atoi calls.  Thus, a lot of time consuming actions are
skipped - many memory allocations/deallocations, heavy string duplication, etc.
The loop metadata only needs line and column info from the source string, so no
allocations and string splitting actually needed.

Patch by Andrey Churbanov

Differential Revision: http://reviews.llvm.org/D21309

Modified:
    openmp/trunk/runtime/src/kmp_itt.inl

Modified: openmp/trunk/runtime/src/kmp_itt.inl
URL: http://llvm.org/viewvc/llvm-project/openmp/trunk/runtime/src/kmp_itt.inl?rev=272698&r1=272697&r2=272698&view=diff
==============================================================================
--- openmp/trunk/runtime/src/kmp_itt.inl (original)
+++ openmp/trunk/runtime/src/kmp_itt.inl Tue Jun 14 14:27:22 2016
@@ -348,17 +348,31 @@ __kmp_itt_metadata_loop( ident_t * loc,
     }
 
     __itt_string_handle * string_handle = __itt_string_handle_create( "omp_metadata_loop");
-    kmp_str_loc_t str_loc = __kmp_str_loc_init( loc->psource, 1 );
+
+    // Parse line and column from psource string: ";file;func;line;col;;"
+    char * s_line;
+    char * s_col;
+    KMP_DEBUG_ASSERT(loc->psource);
+#ifdef __cplusplus
+    s_line = strchr((char*)loc->psource, ';');
+#else
+    s_line = strchr(loc->psource, ';');
+#endif
+    KMP_DEBUG_ASSERT(s_line);
+    s_line = strchr(s_line + 1, ';');   // 2-nd semicolon
+    KMP_DEBUG_ASSERT(s_line);
+    s_line = strchr(s_line + 1, ';');   // 3-rd semicolon
+    KMP_DEBUG_ASSERT(s_line);
+    s_col = strchr(s_line + 1, ';');    // 4-th semicolon
+    KMP_DEBUG_ASSERT(s_col);
 
     kmp_uint64 loop_data[ 5 ];
-    loop_data[ 0 ] = str_loc.line;
-    loop_data[ 1 ] = str_loc.col;
+    loop_data[ 0 ] = atoi(s_line + 1); // read line
+    loop_data[ 1 ] = atoi(s_col + 1);  // read column
     loop_data[ 2 ] = sched_type;
     loop_data[ 3 ] = iterations;
     loop_data[ 4 ] = chunk;
 
-    __kmp_str_loc_free( &str_loc );
-
     __itt_metadata_add(metadata_domain, __itt_null, string_handle, __itt_metadata_u64, 5, loop_data);
 #endif
 } // __kmp_itt_metadata_loop