branches/5.1:

Fix Bug#36600 SHOW STATUS takes a lot of CPU in buf_get_latched_pages_number

by removing the Innodb_buffer_pool_pages_latched variable from
SHOW STATUS output in non-UNIV_DEBUG compilation.
 
Approved by:	Heikki

buf/buf0buf.c

@@ -2328,7 +2328,6 @@ buf_print(void)
 
 	ut_a(buf_validate());
 }
-#endif /* UNIV_DEBUG */
 
 /*************************************************************************
 Returns the number of latched pages in the buffer pool. */
@@ -2361,6 +2360,7 @@ buf_get_latched_pages_number(void)
 
 	return(fixed_pages_number);
 }
+#endif /* UNIV_DEBUG */
 
 /*************************************************************************
 Returns the number of pending buf pool ios. */

handler/ha_innodb.cc

@@ -334,8 +334,10 @@ static SHOW_VAR innodb_status_variables[]= {
   (char*) &export_vars.innodb_buffer_pool_pages_flushed,  SHOW_LONG},
   {"buffer_pool_pages_free",
   (char*) &export_vars.innodb_buffer_pool_pages_free,	  SHOW_LONG},
+#ifdef UNIV_DEBUG
   {"buffer_pool_pages_latched",
   (char*) &export_vars.innodb_buffer_pool_pages_latched,  SHOW_LONG},
+#endif /* UNIV_DEBUG */
   {"buffer_pool_pages_misc",
   (char*) &export_vars.innodb_buffer_pool_pages_misc,	  SHOW_LONG},
   {"buffer_pool_pages_total",

include/buf0buf.h

@@ -495,7 +495,15 @@ Prints info of the buffer pool data structure. */
 void
 buf_print(void);
 /*============*/
+
+/*************************************************************************
+Returns the number of latched pages in the buffer pool. */
+
+ulint
+buf_get_latched_pages_number(void);
+/*==============================*/
 #endif /* UNIV_DEBUG */
+
 /************************************************************************
 Prints a page to stderr. */
 
@@ -503,12 +511,7 @@ void
 buf_page_print(
 /*===========*/
 	byte*	read_buf);	/* in: a database page */
-/*************************************************************************
-Returns the number of latched pages in the buffer pool. */
 
-ulint
-buf_get_latched_pages_number(void);
-/*==============================*/
 /*************************************************************************
 Returns the number of pending buf pool ios. */
 

include/srv0srv.h

@@ -501,7 +501,9 @@ struct export_var_struct{
 	ulint innodb_buffer_pool_pages_dirty;
 	ulint innodb_buffer_pool_pages_misc;
 	ulint innodb_buffer_pool_pages_free;
+#ifdef UNIV_DEBUG
 	ulint innodb_buffer_pool_pages_latched;
+#endif /* UNIV_DEBUG */
 	ulint innodb_buffer_pool_read_requests;
 	ulint innodb_buffer_pool_reads;
 	ulint innodb_buffer_pool_wait_free;

srv/srv0srv.c

@@ -1825,8 +1825,10 @@ srv_export_innodb_status(void)
 		= UT_LIST_GET_LEN(buf_pool->flush_list);
 	export_vars.innodb_buffer_pool_pages_free
 		= UT_LIST_GET_LEN(buf_pool->free);
+#ifdef UNIV_DEBUG
 	export_vars.innodb_buffer_pool_pages_latched
 		= buf_get_latched_pages_number();
+#endif /* UNIV_DEBUG */
 	export_vars.innodb_buffer_pool_pages_total = buf_pool->curr_size;
 
 	export_vars.innodb_buffer_pool_pages_misc = buf_pool->max_size