From owner-svn-src-all@FreeBSD.ORG  Sat May  1 20:44:37 2010
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 8916F106566B;
	Sat,  1 May 2010 20:44:37 +0000 (UTC) (envelope-from mm@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [69.147.83.44])
	by mx1.freebsd.org (Postfix) with ESMTP id 788578FC0C;
	Sat,  1 May 2010 20:44:37 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id o41Kib8X088277;
	Sat, 1 May 2010 20:44:37 GMT (envelope-from mm@svn.freebsd.org)
Received: (from mm@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id o41KibtG088275;
	Sat, 1 May 2010 20:44:37 GMT (envelope-from mm@svn.freebsd.org)
Message-Id: <201005012044.o41KibtG088275@svn.freebsd.org>
From: Martin Matuska <mm@FreeBSD.org>
Date: Sat, 1 May 2010 20:44:37 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r207481 -
	head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
	user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
	<mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 01 May 2010 20:44:37 -0000

Author: mm
Date: Sat May  1 20:44:37 2010
New Revision: 207481
URL: http://svn.freebsd.org/changeset/base/207481

Log:
  Add sysctl and loader tunable vfs.zfs.txg.write_limit_override.
  This tunable improves fine-tuning of ZFS write throttling.
  
  PR:		kern/146108
  Suggested by:	Nikolay Denev <ndenev at gmail.com>
  Approved by:	pjd, delphij (mentor)
  MFC after:	2 weeks

Modified:
  head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c

Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c	Sat May  1 19:53:15 2010	(r207480)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/txg.c	Sat May  1 20:44:37 2010	(r207481)
@@ -38,6 +38,7 @@ static void txg_quiesce_thread(void *arg
 
 int zfs_txg_timeout = 30;	/* max seconds worth of delta per txg */
 extern int zfs_txg_synctime;
+extern uint64_t zfs_write_limit_override;
 
 SYSCTL_DECL(_vfs_zfs);
 SYSCTL_NODE(_vfs_zfs, OID_AUTO, txg, CTLFLAG_RW, 0,
@@ -48,6 +49,11 @@ SYSCTL_INT(_vfs_zfs_txg, OID_AUTO, timeo
 TUNABLE_INT("vfs.zfs.txg.synctime", &zfs_txg_synctime);
 SYSCTL_INT(_vfs_zfs_txg, OID_AUTO, synctime, CTLFLAG_RDTUN, &zfs_txg_synctime,
     0, "Target seconds to sync a txg");
+TUNABLE_QUAD("vfs.zfs.txg.write_limit_override", &zfs_write_limit_override);
+SYSCTL_QUAD(_vfs_zfs_txg, OID_AUTO, write_limit_override, CTLFLAG_RW,
+    &zfs_write_limit_override, 0,
+    "Override maximum size of a txg to this size in bytes, "
+    "value of 0 means don't override");
 
 /*
  * Prepare the txg subsystem.