Issue #26588: Optimize tracemalloc_realloc()

vstinner · vstinner · commit 42bcf37fcffa · 2016-03-23T09:08:08.000+01:00
No need to remove the old trace if the memory block didn't move.
diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
@@ -633,7 +633,12 @@ tracemalloc_realloc(void *ctx, void *ptr, size_t new_size)
         /* an existing memory block has been resized */
 
         TABLES_LOCK();
-        REMOVE_TRACE(ptr);
+
+        /* tracemalloc_add_trace() updates the trace if there is already
+           a trace at address (domain, ptr2) */
+        if (ptr2 != ptr) {
+            REMOVE_TRACE(ptr);
+        }
 
         if (ADD_TRACE(ptr2, new_size) < 0) {
             /* Memory allocation failed. The error cannot be reported to
