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Date:      Thu, 29 Nov 2012 07:30:42 +0000 (UTC)
From:      Andre Oppermann <andre@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r243668 - in head/sys: kern sys
Message-ID:  <201211290730.qAT7Uhkv016745@svn.freebsd.org>
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Author: andre
Date: Thu Nov 29 07:30:42 2012
New Revision: 243668
URL: http://svnweb.freebsd.org/changeset/base/243668

Log:
  Using a long is the wrong type to represent the realmem and maxmbufmem
  variable as they may overflow on i386/PAE and i386 with > 2GB RAM.
  
  Use 64bit quad_t instead.  It has broader kernel infrastructure support
  with TUNABLE_QUAD_FETCH() and qmin/qmax() than other available types.
  
  Pointed out by:	alc, bde

Modified:
  head/sys/kern/subr_param.c
  head/sys/sys/mbuf.h

Modified: head/sys/kern/subr_param.c
==============================================================================
--- head/sys/kern/subr_param.c	Thu Nov 29 06:26:42 2012	(r243667)
+++ head/sys/kern/subr_param.c	Thu Nov 29 07:30:42 2012	(r243668)
@@ -93,7 +93,7 @@ int	ncallout;			/* maximum # of timer ev
 int	nbuf;
 int	ngroups_max;			/* max # groups per process */
 int	nswbuf;
-long	maxmbufmem;			/* max mbuf memory */
+quad_t	maxmbufmem;			/* max mbuf memory */
 pid_t	pid_max = PID_MAX;
 long	maxswzone;			/* max swmeta KVA storage */
 long	maxbcache;			/* max buffer cache KVA storage */
@@ -271,7 +271,7 @@ init_param1(void)
 void
 init_param2(long physpages)
 {
-	long realmem;
+	quad_t realmem;
 
 	/* Base parameters */
 	maxusers = MAXUSERS;
@@ -332,10 +332,10 @@ init_param2(long physpages)
 	 * available kernel memory (physical or kmem).
 	 * At most it can be 3/4 of available kernel memory.
 	 */
-	realmem = lmin(physpages * PAGE_SIZE,
+	realmem = qmin(physpages * PAGE_SIZE,
 			VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS);
 	maxmbufmem = realmem / 2;
-	TUNABLE_LONG_FETCH("kern.maxmbufmem", &maxmbufmem);
+	TUNABLE_QUAD_FETCH("kern.maxmbufmem", &maxmbufmem);
 	if (maxmbufmem > (realmem / 4) * 3)
 		maxmbufmem = (realmem / 4) * 3;
 

Modified: head/sys/sys/mbuf.h
==============================================================================
--- head/sys/sys/mbuf.h	Thu Nov 29 06:26:42 2012	(r243667)
+++ head/sys/sys/mbuf.h	Thu Nov 29 07:30:42 2012	(r243668)
@@ -395,7 +395,7 @@ struct mbstat {
  *
  * The rest of it is defined in kern/kern_mbuf.c
  */
-extern long		maxmbufmem;
+extern quad_t		maxmbufmem;
 extern uma_zone_t	zone_mbuf;
 extern uma_zone_t	zone_clust;
 extern uma_zone_t	zone_pack;

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