branches/zip rb://126

Based on contribution from Google Inc.
This patch introduces a new parameter innodb_io_capacity to control the
rate at which master threads performs various tasks. The default value
is 200 and higher values imply more aggressive flushing and ibuf merges
from within the master thread.
This patch also changes the ibuf merge from synchronous to asynchronous.
Another minor change is not to force the master thread to wait for a
log flush to complete every second.

Approved by: Heikki

handler/ha_innodb.cc

 /*****************************************************************************
 
 Copyright (c) 2000, 2009, MySQL AB & Innobase Oy. All Rights Reserved.
-Copyright (c) 2008, Google Inc.
+Copyright (c) 2008, 2009 Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -9617,6 +9617,11 @@ static MYSQL_SYSVAR_BOOL(doublewrite, innobase_use_doublewrite,
   "Disable with --skip-innodb-doublewrite.",
   NULL, NULL, TRUE);
 
+static MYSQL_SYSVAR_ULONG(io_capacity, srv_io_capacity,
+  PLUGIN_VAR_RQCMDARG,
+  "Number of IOPs the server can do. Tunes the background IO rate",
+  NULL, NULL, 200, 100, ~0L, 0);
+
 static MYSQL_SYSVAR_ULONG(fast_shutdown, innobase_fast_shutdown,
   PLUGIN_VAR_OPCMDARG,
   "Speeds up the shutdown process of the InnoDB storage engine. Possible "
@@ -9902,6 +9907,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(use_sys_malloc),
   MYSQL_SYSVAR(change_buffering),
   MYSQL_SYSVAR(read_ahead_factor),
+  MYSQL_SYSVAR(io_capacity),
   NULL
 };
 

include/log0log.h

@@ -14,6 +14,30 @@ You should have received a copy of the GNU General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place, Suite 330, Boston, MA 02111-1307 USA
 
+*****************************************************************************/
+/*****************************************************************************
+
+Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 2009, Google Inc.
+
+Portions of this file contain modifications contributed and copyrighted by
+Google, Inc. Those modifications are gratefully acknowledged and are described
+briefly in the InnoDB documentation. The contributions by Google are
+incorporated with their permission, and subject to the conditions contained in
+the file COPYING.Google.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+
 *****************************************************************************/
 
 /**************************************************//**
@@ -199,6 +223,16 @@ void
 log_buffer_flush_to_disk(void);
 /*==========================*/
 /****************************************************************//**
+This functions writes the log buffer to the log file and if 'flush'
+is set it forces a flush of the log file as well. This is meant to be
+called from background master thread only as it does not wait for
+the write (+ possible flush) to finish. */
+UNIV_INTERN
+void
+log_buffer_sync_in_background(
+/*==========================*/
+	ibool	flush);	/*<! in: flush the logs to disk */
+/****************************************************************//**
 Advances the smallest lsn for which there are unflushed dirty blocks in the
 buffer pool and also may make a new checkpoint. NOTE: this function may only
 be called if the calling thread owns no synchronization objects!

include/srv0srv.h

 /*****************************************************************************
 
 Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.
-Copyright (c) 2008, Google Inc.
+Copyright (c) 2008, 2009, Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -155,6 +155,13 @@ extern ulint	srv_read_ahead_factor;
 extern ulint	srv_n_read_io_threads;
 extern ulint	srv_n_write_io_threads;
 
+/* Number of IO operations per second the server can do */
+extern ulint    srv_io_capacity;
+/* Returns the number of IO operations that is X percent of the
+capacity. PCT_IO(5) -> returns the number of IO operations that
+is 5% of the max where max is srv_io_capacity.  */
+#define PCT_IO(p) ((ulint) (srv_io_capacity * ((double) p / 100.0)))
+
 #ifdef UNIV_LOG_ARCHIVE
 extern ibool	srv_log_archive_on;
 extern ibool	srv_archive_recovery;

log/log0log.c

@@ -14,6 +14,30 @@ You should have received a copy of the GNU General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place, Suite 330, Boston, MA 02111-1307 USA
 
+*****************************************************************************/
+/*****************************************************************************
+
+Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 2009, Google Inc.
+
+Portions of this file contain modifications contributed and copyrighted by
+Google, Inc. Those modifications are gratefully acknowledged and are described
+briefly in the InnoDB documentation. The contributions by Google are
+incorporated with their permission, and subject to the conditions contained in
+the file COPYING.Google.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+
 *****************************************************************************/
 
 /**************************************************//**
@@ -1533,6 +1557,29 @@ log_buffer_flush_to_disk(void)
 }
 
 /****************************************************************//**
+This functions writes the log buffer to the log file and if 'flush'
+is set it forces a flush of the log file as well. This is meant to be
+called from background master thread only as it does not wait for
+the write (+ possible flush) to finish. */
+UNIV_INTERN
+void
+log_buffer_sync_in_background(
+/*==========================*/
+	ibool	flush)	/*!< in: flush the logs to disk */
+{
+	ib_uint64_t	lsn;
+
+	mutex_enter(&(log_sys->mutex));
+
+	lsn = log_sys->lsn;
+
+	mutex_exit(&(log_sys->mutex));
+
+	log_write_up_to(lsn, LOG_NO_WAIT, flush);
+}
+
+/********************************************************************
+
 Tries to establish a big enough margin of free space in the log buffer, such
 that a new log entry can be catenated without an immediate need for a flush. */
 static