Don't always zero memory in malloc(). This saves around 2us on a

full-length PKB allocation.

diff --git a/src/core/malloc.c b/src/core/malloc.c
index bb34db31528da2808fc952f74b60c31ffd7e500e..db2b500c92da93c58e7b4578d2d891aa3751c3f4 100644 (file)
--- a/src/core/malloc.c
+++ b/src/core/malloc.c
@@ -134,8 +134,6 @@ void * alloc_memblock ( size_t size, size_t align ) {
                         */
                        if ( pre_size < MIN_MEMBLOCK_SIZE )
                                list_del ( &pre->list );
-                       /* Zero allocated memory, for calloc() */
-                       memset ( block, 0, size );
                        DBG ( "Allocated [%p,%p)\n", block,
                              ( ( ( void * ) block ) + size ) );
                        return block;
@@ -297,6 +295,23 @@ void free ( void *ptr ) {
        realloc ( ptr, 0 );
 }
 
+/**
+ * Allocate cleared memory
+ *
+ * @v size             Requested size
+ * @ret ptr            Allocated memory
+ *
+ * Allocate memory as per malloc(), and zero it.
+ */
+void * _calloc ( size_t size ) {
+       void *data;
+
+       data = malloc ( size );
+       if ( data )
+               memset ( data, 0, size );
+       return data;
+}
+
 /**
  * Add memory to allocation pool
  *

diff --git a/src/include/stdlib.h b/src/include/stdlib.h
index 2b6471e1cd4e8042d65992b41014493dbdda7e66..39ad831fc5a8d2934143e0534acd2176f8cfcb17 100644 (file)
--- a/src/include/stdlib.h
+++ b/src/include/stdlib.h
@@ -8,6 +8,8 @@ extern void free ( void *ptr );
 extern int system ( const char *command );
 extern long int random ( void );
 
+extern void * _calloc ( size_t len );
+
 /**
  * Allocate cleared memory
  *
@@ -17,12 +19,12 @@ extern long int random ( void );
  *
  * Allocate memory as per malloc(), and zero it.
  *
- * Note that malloc() and calloc() are identical, in the interests of
- * reducing code size.  Callers should not, however, rely on malloc()
- * clearing memory, since this behaviour may change in future.
+ * This is implemented as a static inline, with the body of the
+ * function in _calloc(), since in most cases @c nmemb will be 1 and
+ * doing the multiply is just wasteful.
  */
 static inline void * calloc ( size_t nmemb, size_t size ) {
-       return malloc ( nmemb * size );
+       return _calloc ( nmemb * size );
 }
 
 #endif /* STDLIB_H */