Merge lp:~gl-az/percona-server/5.5-686534-881001 into lp:percona-server/5.5

[George Ormond Lorch III]

Fixed issue where LRU dump would hold LRU_list_mutex during the entire dump process for each buffer pool. Now the mutex is only held when navigating the buffer pool and filling LRU dump pages but not during the LRU dump disk write. Modified dump page logic to allow number of dump pages that are to be filled on each buffer pool mutex cycle to be specified at compile time.

Fixed issue where innodb_blocking_buffer_pool_restore does not take an optional bool argument similar to other bool options.

Fixed issue where LRU dump would hold LRU_list_mutex during the entire dump process for each buffer pool. Now the mutex is only held when navigating the buffer pool and filling LRU dump pages but not during the LRU dump disk write. Modified dump page logic to allow number of dump pages that are to be filled on each buffer pool mutex cycle to be specified at compile time.

Fixed issue where innodb_blocking_buffer_pool_restore does not take an optional bool argument similar to other bool options.

http://jenkins.percona.com/view/PS%205.5/job/percona-server-5.5-param/515/

[Stewart Smith (stewart)]

review: Approve

=== modified file 'Percona-Server/storage/innobase/buf/buf0lru.c'
--- Percona-Server/storage/innobase/buf/buf0lru.c	2012-09-17 13:08:32 +0000
+++ Percona-Server/storage/innobase/buf/buf0lru.c	2012-09-21 18:10:26 +0000
@@ -2531,6 +2531,14 @@
 Dump the LRU page list to the specific file. */
 #define LRU_DUMP_FILE "ib_lru_dump"
 #define LRU_DUMP_TEMP_FILE "ib_lru_dump.tmp"
+#define LRU_OS_FILE_WRITE() \
+	os_file_write(LRU_DUMP_FILE, dump_file, buffer, \
+		(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL, \
+		(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)), \
+		buffer_size)
+#define LRU_DUMP_PAGE_COUNT	1	/* Specifies how many dump pages
+					   should be filled for each hold
+					   of the LRU_list_mutex. */
 
 UNIV_INTERN
 ibool
@@ -2541,23 +2549,30 @@
 	ibool		success;
 	byte*		buffer_base = NULL;
 	byte*		buffer = NULL;
+	const ulint	buffer_size = LRU_DUMP_PAGE_COUNT * UNIV_PAGE_SIZE;
 	buf_page_t*	bpage;
+	buf_page_t*	first_bpage;
 	ulint		buffers;
 	ulint		offset;
-	ibool		ret = FALSE;
+	ulint		pages_written;
 	ulint		i;
+	ulint		total_pages;
+
+	/* Sanity test to make sure page size is a multiple of 
+	   assumed dump record size */
+	ut_a(UNIV_PAGE_SIZE % 8 == 0);
 
 	for (i = 0; i < srv_n_data_files; i++) {
 		if (strstr(srv_data_file_names[i], LRU_DUMP_FILE) != NULL) {
 			fprintf(stderr,
 				" InnoDB: The name '%s' seems to be used for"
-				" innodb_data_file_path. For safety, dumping of the LRU list"
-				" is not being done.\n", LRU_DUMP_FILE);
+				" innodb_data_file_path. Dumping LRU list is"
+				"  not done for safeness.\n", LRU_DUMP_FILE);
 			goto end;
 		}
 	}
 
-	buffer_base = ut_malloc(2 * UNIV_PAGE_SIZE);
+	buffer_base = ut_malloc(UNIV_PAGE_SIZE + buffer_size);
 	buffer = ut_align(buffer_base, UNIV_PAGE_SIZE);
 	if (!buffer) {
 		fprintf(stderr,
@@ -2577,18 +2592,28 @@
 	}
 
 	buffers = offset = 0;
-
 	for (i = 0; i < srv_buf_pool_instances; i++) {
 		buf_pool_t*	buf_pool;
 
 		buf_pool = buf_pool_from_array(i);
 
 		mutex_enter(&buf_pool->LRU_list_mutex);
-		bpage = UT_LIST_GET_LAST(buf_pool->LRU);
-
-		while (bpage != NULL) {
-			if (offset == 0) {
-				memset(buffer, 0, UNIV_PAGE_SIZE);
+		bpage = first_bpage = UT_LIST_GET_FIRST(buf_pool->LRU);
+		total_pages = UT_LIST_GET_LEN(buf_pool->LRU);
+
+		pages_written = 0;
+		while (bpage != NULL && (pages_written++ < total_pages)) {
+
+			buf_page_t* next_bpage = UT_LIST_GET_NEXT(LRU, bpage);
+
+			if (next_bpage == first_bpage) {
+				/* Do not release list mutex here, it will be
+				   released just outside this while loop */
+				fprintf(stderr,
+					"InnoDB: detected cycle in LRU for"
+					" buffer pool %lu, skipping to next"
+					" buffer pool.\n", i);
+				break;
 			}
 
 			mach_write_to_4(buffer + offset * 4, bpage->space);
@@ -2596,52 +2621,71 @@
 			mach_write_to_4(buffer + offset * 4, bpage->offset);
 			offset++;
 
-			if (offset == UNIV_PAGE_SIZE/4) {
+			ut_a(offset <= buffer_size);
+			if (offset == buffer_size/4) {
+				mutex_t		*next_block_mutex = NULL;
+
 				if (srv_shutdown_state != SRV_SHUTDOWN_NONE) {
-					success = 0;
+					mutex_exit(&buf_pool->LRU_list_mutex);
+					success = FALSE;
 					fprintf(stderr,
 						" InnoDB: stopped dumping lru"
 						" pages because of server"
 						" shutdown.\n");
-				}
-				success = os_file_write(LRU_DUMP_FILE, dump_file, buffer,
-						(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL,
-						(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)),
-						UNIV_PAGE_SIZE);
+					goto end;
+				}
+
+				/* While writing file, release buffer pool
+				   mutex but keep the next page fixed so we
+				   don't worry about our list iterator becoming
+				   invalid */
+				if (next_bpage) {
+					next_block_mutex = buf_page_get_mutex(
+								next_bpage);
+
+					mutex_enter(next_block_mutex);
+					next_bpage->buf_fix_count++;
+					mutex_exit(next_block_mutex);
+				}
+				mutex_exit(&buf_pool->LRU_list_mutex);
+
+				success = LRU_OS_FILE_WRITE();
+
+				/* Grab this here so that next_bpage can't
+				   be purged when we drop the fix_count */
+				mutex_enter(&buf_pool->LRU_list_mutex);
+
+				if (next_bpage) {
+					mutex_enter(next_block_mutex);
+					next_bpage->buf_fix_count--;
+					mutex_exit(next_block_mutex);
+				}
+
 				if (!success) {
 					mutex_exit(&buf_pool->LRU_list_mutex);
 					fprintf(stderr,
-						" InnoDB: cannot write page %lu of %s\n",
+						" InnoDB: cannot write page"
+						" %lu of %s\n",
 						buffers, LRU_DUMP_FILE);
 					goto end;
 				}
 				buffers++;
 				offset = 0;
+
+				bpage = next_bpage;
+			} else {
+				bpage = UT_LIST_GET_NEXT(LRU, bpage);
 			}
-
-			bpage = UT_LIST_GET_PREV(LRU, bpage);
-		}
+		} /* while(bpage ...) */
 		mutex_exit(&buf_pool->LRU_list_mutex);
-	}
-
-	if (offset == 0) {
-		memset(buffer, 0, UNIV_PAGE_SIZE);
-	}
-
-	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
-	offset++;
-	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
-	offset++;
-
-	success = os_file_write(LRU_DUMP_FILE, dump_file, buffer,
-			(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL,
-			(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)),
-			UNIV_PAGE_SIZE);
-	if (!success) {
-		goto end;
-	}
-
-	ret = TRUE;
+	} /* for(srv_buf_pool_instances ...) */
+
+	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
+	offset++;
+	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
+	offset++;
+
+	success = LRU_OS_FILE_WRITE();
 end:
 	if (dump_file != -1) {
 		if (success) {
@@ -2656,7 +2700,7 @@
 	if (buffer_base)
 		ut_free(buffer_base);
 
-	return(ret);
+	return(success);
 }
 
 typedef struct {

=== modified file 'Percona-Server/storage/innobase/handler/ha_innodb.cc'
--- Percona-Server/storage/innobase/handler/ha_innodb.cc	2012-09-17 13:08:32 +0000
+++ Percona-Server/storage/innobase/handler/ha_innodb.cc	2012-09-21 18:10:26 +0000
@@ -12837,7 +12837,7 @@
 
 static MYSQL_SYSVAR_BOOL(blocking_buffer_pool_restore,
   innobase_blocking_lru_restore,
-  PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY,
+  PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_READONLY,
   "Block XtraDB startup process until buffer pool is full restored from a "
   "dump file (if present). Disabled by default.",
   NULL, NULL, FALSE);