From owner-svn-src-stable@FreeBSD.ORG  Wed Oct 15 20:04:22 2014
Return-Path: <owner-svn-src-stable@FreeBSD.ORG>
Delivered-To: svn-src-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 6A6C5D3;
 Wed, 15 Oct 2014 20:04:22 +0000 (UTC)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 5612EA4D;
 Wed, 15 Oct 2014 20:04:22 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id s9FK4MmQ033755;
 Wed, 15 Oct 2014 20:04:22 GMT (envelope-from jkim@FreeBSD.org)
Received: (from jkim@localhost)
 by svn.freebsd.org (8.14.9/8.14.9/Submit) id s9FK4MIO033754;
 Wed, 15 Oct 2014 20:04:22 GMT (envelope-from jkim@FreeBSD.org)
Message-Id: <201410152004.s9FK4MIO033754@svn.freebsd.org>
X-Authentication-Warning: svn.freebsd.org: jkim set sender to jkim@FreeBSD.org
 using -f
From: Jung-uk Kim <jkim@FreeBSD.org>
Date: Wed, 15 Oct 2014 20:04:22 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org
Subject: svn commit: r273150 - stable/10/sys/kern
X-SVN-Group: stable-10
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-stable@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: SVN commit messages for all the -stable branches of the src tree
 <svn-src-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-stable>,
 <mailto:svn-src-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-stable/>
List-Post: <mailto:svn-src-stable@freebsd.org>
List-Help: <mailto:svn-src-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-stable>,
 <mailto:svn-src-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 15 Oct 2014 20:04:22 -0000

Author: jkim
Date: Wed Oct 15 20:04:21 2014
New Revision: 273150
URL: https://svnweb.freebsd.org/changeset/base/273150

Log:
  MFC:	r272718
  
  Make kern.nswbuf tunable from loader.

Modified:
  stable/10/sys/kern/vfs_bio.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/vfs_bio.c
==============================================================================
--- stable/10/sys/kern/vfs_bio.c	Wed Oct 15 19:59:43 2014	(r273149)
+++ stable/10/sys/kern/vfs_bio.c	Wed Oct 15 20:04:21 2014	(r273150)
@@ -636,6 +636,10 @@ bd_speedup(void)
 	mtx_unlock(&bdlock);
 }
 
+#ifndef NSWBUF_MIN
+#define	NSWBUF_MIN	16
+#endif
+
 #ifdef __i386__
 #define	TRANSIENT_DENOM	5
 #else
@@ -747,11 +751,10 @@ kern_vfs_bio_buffer_alloc(caddr_t v, lon
 	 * swbufs are used as temporary holders for I/O, such as paging I/O.
 	 * We have no less then 16 and no more then 256.
 	 */
-	nswbuf = max(min(nbuf/4, 256), 16);
-#ifdef NSWBUF_MIN
+	nswbuf = min(nbuf / 4, 256);
+	TUNABLE_INT_FETCH("kern.nswbuf", &nswbuf);
 	if (nswbuf < NSWBUF_MIN)
 		nswbuf = NSWBUF_MIN;
-#endif
 
 	/*
 	 * Reserve space for the buffer cache buffers