Bug #12950803 62294: BUF_BUDDY_RELOCATE CALLS GETTIMEOFDAY ...

buf_buddy_relocate(): The ut_time_us() function is needed for
statistics, calculating the total time spent on relocating blocks.
Until now, we invoked ut_time_us() every time buf_buddy_relocate() was
called. Fix: Only call ut_time_us() when the block can be relocated.
After this fix, the reported relocated_usec will no longer include the
time for the page_hash lookup and for acquiring the block mutex.

Approved by Sunny Bains on IM

storage/innodb_plugin/ChangeLog

+2011-09-06	The InnoDB Team
+
+	* buf/buf0buddy.c:
+	Fix Bug#12950803 62294: BUF_BUDDY_RELOCATE CALLS GETTIMEOFDAY
+	WHILE HOLDING BUFFER POOL MUTEX
+
 2011-09-06	The InnoDB Team
 
 	* include/trx0undo.h, trx/trx0rec.c, trx/trx0undo.c:

storage/innodb_plugin/buf/buf0buddy.c

@@ -327,7 +327,6 @@ buf_buddy_relocate(
 {
 	buf_page_t*	bpage;
 	const ulint	size	= BUF_BUDDY_LOW << i;
-	ullint		usec	= ut_time_us(NULL);
 	mutex_t*	mutex;
 	ulint		space;
 	ulint		page_no;
@@ -394,6 +393,7 @@ buf_buddy_relocate(
 
 	if (buf_page_can_relocate(bpage)) {
 		/* Relocate the compressed page. */
+		ullint	usec	= ut_time_us(NULL);
 		ut_a(bpage->zip.data == src);
 		memcpy(dst, src, size);
 		bpage->zip.data = dst;