slab: document kzfree() zeroing behavior

As suggested by Alan Cox, document the fact that kzfree() can zero out a great deal more memory than the what the user requested from kmalloc(). Cc: Alan Cox <[email protected]> Signed-off-by: Pekka Enberg <[email protected]>
caseydunham · Jun 1, 2009 · a234bdc · a234bdc
1 parent 59a3759
commit a234bdc
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/mm/util.c b/mm/util.c
@@ -166,6 +166,10 @@ EXPORT_SYMBOL(krealloc);
  *
  * The memory of the object @p points to is zeroed before freed.
  * If @p is %NULL, kzfree() does nothing.
+ *
+ * Note: this function zeroes the whole allocated buffer which can be a good
+ * deal bigger than the requested buffer size passed to kmalloc(). So be
+ * careful when using this function in performance sensitive code.
  */
 void kzfree(const void *p)
 {