branches/zip rb://147

Done away with following two status variables:

innodb_buffer_pool_read_ahead_rnd
innodb_buffer_pool_read_ahead_seq

Introduced two new status variables:
innodb_buffer_pool_read_ahead = number of pages read as part of
readahead since server startup
innodb_buffer_pool_read_ahead_evicted = number of pages that are read
in as readahead but were evicted before ever being accessed since
server startup i.e.: a measure of how badly our readahead is
performing

SHOW INNODB STATUS will show two extra numbers in buffer pool section:
pages read ahead/sec and pages evicted without access/sec

Approved by: Marko

btr/btr0sea.c

@@ -957,7 +957,7 @@ btr_search_guess_on_hash(
 	/* Increment the page get statistics though we did not really
 	fix the page: for user info only */
 
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 
 	return(TRUE);
 

buf/buf0buf.c

@@ -1622,7 +1622,7 @@ buf_page_get_zip(
 #ifndef UNIV_LOG_DEBUG
 	ut_ad(!ibuf_inside());
 #endif
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 
 	for (;;) {
 		buf_pool_mutex_enter();
@@ -1991,7 +1991,7 @@ buf_page_get_gen(
 #ifndef UNIV_LOG_DEBUG
 	ut_ad(!ibuf_inside() || ibuf_page(space, zip_size, offset, NULL));
 #endif
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 loop:
 	block = guess;
 	buf_pool_mutex_enter();
@@ -2410,7 +2410,7 @@ buf_page_optimistic_get_func(
 	ut_a(ibuf_count_get(buf_block_get_space(block),
 			    buf_block_get_page_no(block)) == 0);
 #endif
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 
 	return(TRUE);
 }
@@ -2504,7 +2504,7 @@ buf_page_get_known_nowait(
 	     || (ibuf_count_get(buf_block_get_space(block),
 				buf_block_get_page_no(block)) == 0));
 #endif
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 
 	return(TRUE);
 }
@@ -2580,7 +2580,7 @@ buf_page_try_get_func(
 #endif /* UNIV_DEBUG_FILE_ACCESSES */
 	buf_block_dbg_add_level(block, SYNC_NO_ORDER_CHECK);
 
-	buf_pool->n_page_gets++;
+	buf_pool->stat.n_page_gets++;
 
 #ifdef UNIV_IBUF_COUNT_DEBUG
 	ut_a(ibuf_count_get(buf_block_get_space(block),
@@ -2944,7 +2944,7 @@ buf_page_create(
 	buf_LRU_add_block(&block->page, FALSE);
 
 	buf_block_buf_fix_inc(block, __FILE__, __LINE__);
-	buf_pool->n_pages_created++;
+	buf_pool->stat.n_pages_created++;
 
 	if (zip_size) {
 		void*	data;
@@ -3192,7 +3192,7 @@ corrupt:
 
 		ut_ad(buf_pool->n_pend_reads > 0);
 		buf_pool->n_pend_reads--;
-		buf_pool->n_pages_read++;
+		buf_pool->stat.n_pages_read++;
 
 		if (uncompressed) {
 			rw_lock_x_unlock_gen(&((buf_block_t*) bpage)->lock,
@@ -3212,7 +3212,7 @@ corrupt:
 					     BUF_IO_WRITE);
 		}
 
-		buf_pool->n_pages_written++;
+		buf_pool->stat.n_pages_written++;
 
 		break;
 
@@ -3530,10 +3530,11 @@ buf_print(void)
 		(ulong) buf_pool->n_flush[BUF_FLUSH_LRU],
 		(ulong) buf_pool->n_flush[BUF_FLUSH_LIST],
 		(ulong) buf_pool->n_flush[BUF_FLUSH_SINGLE_PAGE],
-		(ulong) buf_pool->n_pages_made_young,
-		(ulong) buf_pool->n_pages_not_made_young,
-		(ulong) buf_pool->n_pages_read, buf_pool->n_pages_created,
-		(ulong) buf_pool->n_pages_written);
+		(ulong) buf_pool->stat.n_pages_made_young,
+		(ulong) buf_pool->stat.n_pages_not_made_young,
+		(ulong) buf_pool->stat.n_pages_read,
+		(ulong) buf_pool->stat.n_pages_created,
+		(ulong) buf_pool->stat.n_pages_written);
 
 	/* Count the number of blocks belonging to each index in the buffer */
 
@@ -3767,61 +3768,66 @@ buf_print_io(
 	current_time = time(NULL);
 	time_elapsed = 0.001 + difftime(current_time,
 					buf_pool->last_printout_time);
-	buf_pool->last_printout_time = current_time;
 
 	fprintf(file,
 		"Pages made young %lu, not young %lu\n"
 		"%.2f youngs/s, %.2f non-youngs/s\n"
 		"Pages read %lu, created %lu, written %lu\n"
 		"%.2f reads/s, %.2f creates/s, %.2f writes/s\n",
-		(ulong) buf_pool->n_pages_made_young,
-		(ulong) buf_pool->n_pages_not_made_young,
-		(buf_pool->n_pages_made_young
-		 - buf_pool->n_pages_made_young_old)
+		(ulong) buf_pool->stat.n_pages_made_young,
+		(ulong) buf_pool->stat.n_pages_not_made_young,
+		(buf_pool->stat.n_pages_made_young
+		 - buf_pool->old_stat.n_pages_made_young)
 		/ time_elapsed,
-		(buf_pool->n_pages_not_made_young
-		 - buf_pool->n_pages_not_made_young_old)
+		(buf_pool->stat.n_pages_not_made_young
+		 - buf_pool->old_stat.n_pages_not_made_young)
 		/ time_elapsed,
-		(ulong) buf_pool->n_pages_read,
-		(ulong) buf_pool->n_pages_created,
-		(ulong) buf_pool->n_pages_written,
-		(buf_pool->n_pages_read - buf_pool->n_pages_read_old)
+		(ulong) buf_pool->stat.n_pages_read,
+		(ulong) buf_pool->stat.n_pages_created,
+		(ulong) buf_pool->stat.n_pages_written,
+		(buf_pool->stat.n_pages_read
+		 - buf_pool->old_stat.n_pages_read)
 		/ time_elapsed,
-		(buf_pool->n_pages_created - buf_pool->n_pages_created_old)
+		(buf_pool->stat.n_pages_created
+		 - buf_pool->old_stat.n_pages_created)
 		/ time_elapsed,
-		(buf_pool->n_pages_written - buf_pool->n_pages_written_old)
+		(buf_pool->stat.n_pages_written
+		 - buf_pool->old_stat.n_pages_written)
 		/ time_elapsed);
 
-	n_gets_diff = buf_pool->n_page_gets - buf_pool->n_page_gets_old;
+	n_gets_diff = buf_pool->stat.n_page_gets - buf_pool->old_stat.n_page_gets;
 
 	if (n_gets_diff) {
 		fprintf(file,
 			"Buffer pool hit rate %lu / 1000,"
 			" young-making rate %lu / 1000 not %lu / 1000\n",
 			(ulong)
-			(1000 - ((1000 * (buf_pool->n_pages_read
-					  - buf_pool->n_pages_read_old))
-				 / n_gets_diff)),
+			(1000 - ((1000 * (buf_pool->stat.n_pages_read
+					  - buf_pool->old_stat.n_pages_read))
+				 / (buf_pool->stat.n_page_gets
+				    - buf_pool->old_stat.n_page_gets))),
 			(ulong)
-			(1000 * (buf_pool->n_pages_made_young
-				 - buf_pool->n_pages_made_young_old)
+			(1000 * (buf_pool->stat.n_pages_made_young
+				 - buf_pool->old_stat.n_pages_made_young)
 			 / n_gets_diff),
 			(ulong)
-			(1000 * (buf_pool->n_pages_not_made_young
-				 - buf_pool->n_pages_not_made_young_old)
+			(1000 * (buf_pool->stat.n_pages_not_made_young
+				 - buf_pool->old_stat.n_pages_not_made_young)
 			 / n_gets_diff));
 	} else {
 		fputs("No buffer pool page gets since the last printout\n",
 		      file);
 	}
 
-	buf_pool->n_page_gets_old = buf_pool->n_page_gets;
-	buf_pool->n_pages_made_young_old = buf_pool->n_pages_made_young;
-	buf_pool->n_pages_not_made_young_old
-		= buf_pool->n_pages_not_made_young;
-	buf_pool->n_pages_read_old = buf_pool->n_pages_read;
-	buf_pool->n_pages_created_old = buf_pool->n_pages_created;
-	buf_pool->n_pages_written_old = buf_pool->n_pages_written;
+	/* Statistics about read ahead algorithm */
+	fprintf(file, "Pages read ahead %.2f/s,"
+		" evicted without access %.2f/s\n",
+		(buf_pool->stat.n_ra_pages_read
+		- buf_pool->old_stat.n_ra_pages_read)
+		/ time_elapsed,
+		(buf_pool->stat.n_ra_pages_evicted
+		- buf_pool->old_stat.n_ra_pages_evicted)
+		/ time_elapsed);
 
 	/* Print some values to help us with visualizing what is
 	happening with LRU eviction. */
@@ -3833,6 +3839,7 @@ buf_print_io(
 		buf_LRU_stat_sum.io, buf_LRU_stat_cur.io,
 		buf_LRU_stat_sum.unzip, buf_LRU_stat_cur.unzip);
 
+	buf_refresh_io_stats();
 	buf_pool_mutex_exit();
 }
 
@@ -3844,10 +3851,7 @@ buf_refresh_io_stats(void)
 /*======================*/
 {
 	buf_pool->last_printout_time = time(NULL);
-	buf_pool->n_page_gets_old = buf_pool->n_page_gets;
-	buf_pool->n_pages_read_old = buf_pool->n_pages_read;
-	buf_pool->n_pages_created_old = buf_pool->n_pages_created;
-	buf_pool->n_pages_written_old = buf_pool->n_pages_written;
+	buf_pool->old_stat = buf_pool->stat;
 }
 
 /*********************************************************************//**

buf/buf0lru.c

@@ -576,6 +576,7 @@ buf_LRU_free_from_common_LRU_list(
 	     bpage = UT_LIST_GET_PREV(LRU, bpage), distance--) {
 
 		enum buf_lru_free_block_status	freed;
+		unsigned			accessed;
 		mutex_t*			block_mutex
 			= buf_page_get_mutex(bpage);
 
@@ -583,11 +584,18 @@ buf_LRU_free_from_common_LRU_list(
 		ut_ad(bpage->in_LRU_list);
 
 		mutex_enter(block_mutex);
+		accessed = buf_page_is_accessed(bpage);
 		freed = buf_LRU_free_block(bpage, TRUE, NULL);
 		mutex_exit(block_mutex);
 
 		switch (freed) {
 		case BUF_LRU_FREED:
+			/* Keep track of pages that are evicted without
+			ever being accessed. This gives us a measure of
+			the effectiveness of readahead */
+			if (!accessed) {
+				++buf_pool->stat.n_ra_pages_evicted;
+			}
 			return(TRUE);
 
 		case BUF_LRU_NOT_FREED:
@@ -1270,7 +1278,7 @@ buf_LRU_make_block_young(
 	buf_page_t*	bpage)	/*!< in: control block */
 {
 	ut_ad(buf_pool_mutex_own());
-	buf_pool->n_pages_made_young++;
+	buf_pool->stat.n_pages_made_young++;
 
 	buf_LRU_remove_block(bpage);
 	buf_LRU_add_block_low(bpage, FALSE);

buf/buf0rea.c

@@ -489,7 +489,7 @@ buf_read_ahead_linear(
 	LRU policy decision. */
 	buf_LRU_stat_inc_io();
 
-	++srv_read_ahead_seq;
+	buf_pool->stat.n_ra_pages_read += count;
 	return(count);
 }
 

handler/ha_innodb.cc

@@ -500,10 +500,10 @@ static SHOW_VAR innodb_status_variables[]= {
   (char*) &export_vars.innodb_buffer_pool_pages_misc,	  SHOW_LONG},
   {"buffer_pool_pages_total",
   (char*) &export_vars.innodb_buffer_pool_pages_total,	  SHOW_LONG},
-  {"buffer_pool_read_ahead_rnd",
-  (char*) &export_vars.innodb_buffer_pool_read_ahead_rnd, SHOW_LONG},
-  {"buffer_pool_read_ahead_seq",
-  (char*) &export_vars.innodb_buffer_pool_read_ahead_seq, SHOW_LONG},
+  {"buffer_pool_read_ahead",
+  (char*) &export_vars.innodb_buffer_pool_read_ahead,	  SHOW_LONG},
+  {"buffer_pool_read_ahead_evicted",
+  (char*) &export_vars.innodb_buffer_pool_read_ahead_evicted, SHOW_LONG},
   {"buffer_pool_read_requests",
   (char*) &export_vars.innodb_buffer_pool_read_requests,  SHOW_LONG},
   {"buffer_pool_reads",

include/buf0buf.h

@@ -1284,6 +1284,31 @@ Compute the hash fold value for blocks in buf_pool->zip_hash. */
 #define BUF_POOL_ZIP_FOLD_BPAGE(b) BUF_POOL_ZIP_FOLD((buf_block_t*) (b))
 /* @} */
 
+/** @brief The buffer pool statistics structure. */
+struct buf_pool_stat_struct{
+	ulint	n_page_gets;	/*!< number of page gets performed;
+				also successful searches through
+				the adaptive hash index are
+				counted as page gets; this field
+				is NOT protected by the buffer
+				pool mutex */
+	ulint	n_pages_read;	/*!< number read operations */
+	ulint	n_pages_written;/*!< number write operations */
+	ulint	n_pages_created;/*!< number of pages created
+				in the pool with no read */
+	ulint	n_ra_pages_read;/*!< number of pages read in
+				as part of read ahead */
+	ulint	n_ra_pages_evicted;/*!< number of read ahead
+				pages that are evicted without
+				being accessed */
+	ulint	n_pages_made_young; /*!< number of pages made young, in
+				calls to buf_LRU_make_block_young() */
+	ulint	n_pages_not_made_young; /*!< number of pages not made
+				young because the first access
+				was not long enough ago, in
+				buf_page_peek_if_too_old() */
+};
+
 /** @brief The buffer pool structure.
 
 NOTE! The definition appears here only for other modules of this
@@ -1311,44 +1336,13 @@ struct buf_pool_struct{
 	time_t		last_printout_time;
 					/*!< when buf_print_io was last time
 					called */
-	ulint		n_pages_made_young;
-					/*!< number of pages made young, in
-					calls to buf_LRU_make_block_young() */
-	ulint		n_pages_not_made_young;
-					/*!< number of pages not made
-					young because the first access
-					was not long enough ago, in
-					buf_page_peek_if_too_old() */
-	ulint		n_pages_read;	/*!< number read operations */
-	ulint		n_pages_written;/*!< number write operations */
-	ulint		n_pages_created;/*!< number of pages created
-					in the pool with no read */
-	ulint		n_page_gets;	/*!< number of page gets performed;
-					also successful searches through
-					the adaptive hash index are
-					counted as page gets; this field
-					is NOT protected by the buffer
-					pool mutex */
-	ulint		n_page_gets_old;/*!< n_page_gets when buf_print_io was
-					called last time: used to calculate
-					hit rate */
-	ulint		n_pages_made_young_old;
-					/*!< n_pages_made_young when
-					buf_print_io was called last time */
-	ulint		n_pages_not_made_young_old;
-					/*!< n_pages_not_made_young when
-					buf_print_io was called last time */
-	ulint		n_pages_read_old;
-					/*!< n_pages_read when buf_print_io
-					was called last time */
-	ulint		n_pages_written_old;
-					/*!< n_pages_written when buf_print_io
-					was called last time */
-	ulint		n_pages_created_old;
-					/*!< n_pages_created when buf_print_io
-					was called last time */
+	buf_pool_stat_t	stat;		/*!< current statistics */
+	buf_pool_stat_t	old_stat;	/*!< old statistics */
+
 	/* @} */
+
 	/** @name Page flushing algorithm fields */
+
 	/* @{ */
 
 	UT_LIST_BASE_NODE_T(buf_page_t) flush_list;

include/buf0buf.ic

@@ -80,7 +80,7 @@ buf_page_peek_if_too_old(
 			return(TRUE);
 		}
 
-		buf_pool->n_pages_not_made_young++;
+		buf_pool->stat.n_pages_not_made_young++;
 		return(FALSE);
 	} else {
 		/* FIXME: bpage->freed_page_clock is 31 bits */

include/buf0types.h

@@ -34,6 +34,8 @@ typedef	struct buf_block_struct		buf_block_t;
 typedef struct buf_chunk_struct		buf_chunk_t;
 /** Buffer pool comprising buf_chunk_t */
 typedef	struct buf_pool_struct		buf_pool_t;
+/** Buffer pool statistics struct */
+typedef	struct buf_pool_stat_struct	buf_pool_stat_t;
 
 /** A buffer frame. @see page_t */
 typedef	byte	buf_frame_t;

include/srv0srv.h

@@ -315,10 +315,6 @@ extern ulint srv_buf_pool_flushed;
 /** Number of buffer pool reads that led to the
 reading of a disk page */
 extern ulint srv_buf_pool_reads;
-/** Number of sequential read-aheads */
-extern ulint srv_read_ahead_seq;
-/** Number of random read-aheads */
-extern ulint srv_read_ahead_rnd;
 
 /** Status variables to be passed to MySQL */
 typedef struct export_var_struct export_struc;
@@ -605,13 +601,13 @@ struct export_var_struct{
 #ifdef UNIV_DEBUG
 	ulint innodb_buffer_pool_pages_latched;	/*!< Latched pages */
 #endif /* UNIV_DEBUG */
-	ulint innodb_buffer_pool_read_requests;	/*!< buf_pool->n_page_gets */
+	ulint innodb_buffer_pool_read_requests;	/*!< buf_pool->stat.n_page_gets */
 	ulint innodb_buffer_pool_reads;		/*!< srv_buf_pool_reads */
 	ulint innodb_buffer_pool_wait_free;	/*!< srv_buf_pool_wait_free */
 	ulint innodb_buffer_pool_pages_flushed;	/*!< srv_buf_pool_flushed */
 	ulint innodb_buffer_pool_write_requests;/*!< srv_buf_pool_write_requests */
-	ulint innodb_buffer_pool_read_ahead_seq;/*!< srv_read_ahead_seq */
-	ulint innodb_buffer_pool_read_ahead_rnd;/*!< srv_read_ahead_rnd */
+	ulint innodb_buffer_pool_read_ahead;	/*!< srv_read_ahead */
+	ulint innodb_buffer_pool_read_ahead_evicted;/*!< srv_read_ahead evicted*/
 	ulint innodb_dblwr_pages_written;	/*!< srv_dblwr_pages_written */
 	ulint innodb_dblwr_writes;		/*!< srv_dblwr_writes */
 	ibool innodb_have_atomic_builtins;	/*!< HAVE_ATOMIC_BUILTINS */
@@ -623,9 +619,9 @@ struct export_var_struct{
 	ulint innodb_os_log_pending_writes;	/*!< srv_os_log_pending_writes */
 	ulint innodb_os_log_pending_fsyncs;	/*!< fil_n_pending_log_flushes */
 	ulint innodb_page_size;			/*!< UNIV_PAGE_SIZE */
-	ulint innodb_pages_created;		/*!< buf_pool->n_pages_created */
-	ulint innodb_pages_read;		/*!< buf_pool->n_pages_read */
-	ulint innodb_pages_written;		/*!< buf_pool->n_pages_written */
+	ulint innodb_pages_created;		/*!< buf_pool->stat.n_pages_created */
+	ulint innodb_pages_read;		/*!< buf_pool->stat.n_pages_read */
+	ulint innodb_pages_written;		/*!< buf_pool->stat.n_pages_written */
 	ulint innodb_row_lock_waits;		/*!< srv_n_lock_wait_count */
 	ulint innodb_row_lock_current_waits;	/*!< srv_n_lock_wait_current_count */
 	ib_int64_t innodb_row_lock_time;	/*!< srv_n_lock_wait_time

srv/srv0srv.c

@@ -292,12 +292,6 @@ UNIV_INTERN ulint srv_buf_pool_flushed = 0;
 reading of a disk page */
 UNIV_INTERN ulint srv_buf_pool_reads = 0;
 
-/** Number of sequential read-aheads */
-UNIV_INTERN ulint srv_read_ahead_seq = 0;
-
-/** Number of random read-aheads */
-UNIV_INTERN ulint srv_read_ahead_rnd = 0;
-
 /* structure to pass status variables to MySQL */
 UNIV_INTERN export_struc export_vars;
 
@@ -464,8 +458,6 @@ static ulint   srv_main_background_loops	= 0;
 static ulint   srv_main_flush_loops		= 0;
 /* Log writes involving flush. */
 static ulint   srv_log_writes_and_flush		= 0;
-/* Log writes not including flush. */
-static ulint   srv_log_buffer_writes		= 0;
 
 /* This is only ever touched by the master thread. It records the
 time when the last flush of log file has happened. The master
@@ -714,9 +706,8 @@ srv_print_master_thread_info(
 		srv_main_1_second_loops, srv_main_sleeps,
 		srv_main_10_second_loops, srv_main_background_loops,
 		srv_main_flush_loops);
-	fprintf(file, "srv_master_thread log flush and writes: %lu "
-		      " log writes only: %lu\n",
-		      srv_log_writes_and_flush, srv_log_buffer_writes);
+	fprintf(file, "srv_master_thread log flush and writes: %lu\n",
+		      srv_log_writes_and_flush);
 }
 
 /*********************************************************************//**
@@ -1877,14 +1868,16 @@ srv_export_innodb_status(void)
 	export_vars.innodb_data_reads = os_n_file_reads;
 	export_vars.innodb_data_writes = os_n_file_writes;
 	export_vars.innodb_data_written = srv_data_written;
-	export_vars.innodb_buffer_pool_read_requests = buf_pool->n_page_gets;
+	export_vars.innodb_buffer_pool_read_requests = buf_pool->stat.n_page_gets;
 	export_vars.innodb_buffer_pool_write_requests
 		= srv_buf_pool_write_requests;
 	export_vars.innodb_buffer_pool_wait_free = srv_buf_pool_wait_free;
 	export_vars.innodb_buffer_pool_pages_flushed = srv_buf_pool_flushed;
 	export_vars.innodb_buffer_pool_reads = srv_buf_pool_reads;
-	export_vars.innodb_buffer_pool_read_ahead_rnd = srv_read_ahead_rnd;
-	export_vars.innodb_buffer_pool_read_ahead_seq = srv_read_ahead_seq;
+	export_vars.innodb_buffer_pool_read_ahead
+		= buf_pool->stat.n_ra_pages_read;
+	export_vars.innodb_buffer_pool_read_ahead_evicted
+		= buf_pool->stat.n_ra_pages_evicted;
 	export_vars.innodb_buffer_pool_pages_data
 		= UT_LIST_GET_LEN(buf_pool->LRU);
 	export_vars.innodb_buffer_pool_pages_dirty
@@ -1915,9 +1908,9 @@ srv_export_innodb_status(void)
 	export_vars.innodb_log_writes = srv_log_writes;
 	export_vars.innodb_dblwr_pages_written = srv_dblwr_pages_written;
 	export_vars.innodb_dblwr_writes = srv_dblwr_writes;
-	export_vars.innodb_pages_created = buf_pool->n_pages_created;
-	export_vars.innodb_pages_read = buf_pool->n_pages_read;
-	export_vars.innodb_pages_written = buf_pool->n_pages_written;
+	export_vars.innodb_pages_created = buf_pool->stat.n_pages_created;
+	export_vars.innodb_pages_read = buf_pool->stat.n_pages_read;
+	export_vars.innodb_pages_written = buf_pool->stat.n_pages_written;
 	export_vars.innodb_row_lock_waits = srv_n_lock_wait_count;
 	export_vars.innodb_row_lock_current_waits
 		= srv_n_lock_wait_current_count;
@@ -2284,12 +2277,6 @@ srv_sync_log_buffer_in_background(void)
 		log_buffer_sync_in_background(TRUE);
 		srv_last_log_flush_time = current_time;
 		srv_log_writes_and_flush++;
-	} else {
-		/* Actually we don't need to write logs here.
-		We are just being extra safe here by forcing
-		the log buffer to log file. */
-		log_buffer_sync_in_background(FALSE);
-		srv_log_buffer_writes++;
 	}
 }
 
@@ -2340,8 +2327,8 @@ loop:
 
 	srv_main_thread_op_info = "reserving kernel mutex";
 
-	n_ios_very_old = log_sys->n_log_ios + buf_pool->n_pages_read
-		+ buf_pool->n_pages_written;
+	n_ios_very_old = log_sys->n_log_ios + buf_pool->stat.n_pages_read
+		+ buf_pool->stat.n_pages_written;
 	mutex_enter(&kernel_mutex);
 
 	/* Store the user activity counter at the start of this loop */
@@ -2361,8 +2348,8 @@ loop:
 	skip_sleep = FALSE;
 
 	for (i = 0; i < 10; i++) {
-		n_ios_old = log_sys->n_log_ios + buf_pool->n_pages_read
-			+ buf_pool->n_pages_written;
+		n_ios_old = log_sys->n_log_ios + buf_pool->stat.n_pages_read
+			+ buf_pool->stat.n_pages_written;
 		srv_main_thread_op_info = "sleeping";
 		srv_main_1_second_loops++;
 
@@ -2401,8 +2388,8 @@ loop:
 
 		n_pend_ios = buf_get_n_pending_ios()
 			+ log_sys->n_pending_writes;
-		n_ios = log_sys->n_log_ios + buf_pool->n_pages_read
-			+ buf_pool->n_pages_written;
+		n_ios = log_sys->n_log_ios + buf_pool->stat.n_pages_read
+			+ buf_pool->stat.n_pages_written;
 		if (n_pend_ios < SRV_PEND_IO_THRESHOLD
 		    && (n_ios - n_ios_old < SRV_RECENT_IO_ACTIVITY)) {
 			srv_main_thread_op_info = "doing insert buffer merge";
@@ -2418,6 +2405,8 @@ loop:
 			/* Try to keep the number of modified pages in the
 			buffer pool under the limit wished by the user */
 
+			srv_main_thread_op_info =
+				"flushing buffer pool pages";
 			n_pages_flushed = buf_flush_batch(BUF_FLUSH_LIST,
 							  PCT_IO(100),
 							  IB_ULONGLONG_MAX);
@@ -2436,6 +2425,8 @@ loop:
 			ulint n_flush = buf_flush_get_desired_flush_rate();
 
 			if (n_flush) {
+				srv_main_thread_op_info =
+					"flushing buffer pool pages";
 				n_flush = ut_min(PCT_IO(100), n_flush);
 				n_pages_flushed =
 					buf_flush_batch(
@@ -2473,8 +2464,8 @@ loop:
 	are not required, and may be disabled. */
 
 	n_pend_ios = buf_get_n_pending_ios() + log_sys->n_pending_writes;
-	n_ios = log_sys->n_log_ios + buf_pool->n_pages_read
-		+ buf_pool->n_pages_written;
+	n_ios = log_sys->n_log_ios + buf_pool->stat.n_pages_read
+		+ buf_pool->stat.n_pages_written;
 
 	srv_main_10_second_loops++;
 	if (n_pend_ios < SRV_PEND_IO_THRESHOLD