From owner-svn-src-head@FreeBSD.ORG Tue Aug 14 17:01:22 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1B4871065672; Tue, 14 Aug 2012 17:01:22 +0000 (UTC) (envelope-from des@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 048318FC12; Tue, 14 Aug 2012 17:01:22 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q7EH1L2x023608; Tue, 14 Aug 2012 17:01:21 GMT (envelope-from des@svn.freebsd.org) Received: (from des@localhost) by svn.freebsd.org (8.14.4/8.14.4/Submit) id q7EH1LVD023603; Tue, 14 Aug 2012 17:01:21 GMT (envelope-from des@svn.freebsd.org) Message-Id: <201208141701.q7EH1LVD023603@svn.freebsd.org> From: Dag-Erling Smørgrav Date: Tue, 14 Aug 2012 17:01:21 +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: r239255 - in head/sys: amd64/include boot/common i386/include X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Aug 2012 17:01:22 -0000 Author: des Date: Tue Aug 14 17:01:21 2012 New Revision: 239255 URL: http://svn.freebsd.org/changeset/base/239255 Log: As discussed on -current, remove the hardcoded default maxswzone. MFC after: 3 weeks Modified: head/sys/amd64/include/param.h head/sys/boot/common/loader.8 head/sys/i386/include/param.h Modified: head/sys/amd64/include/param.h ============================================================================== --- head/sys/amd64/include/param.h Tue Aug 14 14:07:34 2012 (r239254) +++ head/sys/amd64/include/param.h Tue Aug 14 17:01:21 2012 (r239255) @@ -123,14 +123,6 @@ #define KSTACK_GUARD_PAGES 1 /* pages of kstack guard; 0 disables */ /* - * Ceiling on amount of swblock kva space, can be changed via - * the kern.maxswzone /boot/loader.conf variable. - */ -#ifndef VM_SWZONE_SIZE_MAX -#define VM_SWZONE_SIZE_MAX (32 * 1024 * 1024) -#endif - -/* * Mach derived conversion macros */ #define round_page(x) ((((unsigned long)(x)) + PAGE_MASK) & ~(PAGE_MASK)) Modified: head/sys/boot/common/loader.8 ============================================================================== --- head/sys/boot/common/loader.8 Tue Aug 14 14:07:34 2012 (r239254) +++ head/sys/boot/common/loader.8 Tue Aug 14 17:01:21 2012 (r239255) @@ -613,17 +613,26 @@ Not all architectures use such buffers; for details. .It Va kern.maxswzone Limits the amount of KVM to be used to hold swap -meta information, which directly governs the -maximum amount of swap the system can support. -This value is specified in bytes of KVA space -and defaults to 32MBytes on i386 and amd64. -Care should be taken -to not reduce this value such that the actual -amount of configured swap exceeds 1/2 the -kernel-supported swap. -The default of 32MB allows -the kernel to support a maximum of ~7GB of swap. -Only change +metadata, which directly governs the +maximum amount of swap the system can support, +at the rate of approximately 200 MB of swap space +per 1 MB of metadata. +This value is specified in bytes of KVA space. +If no value is provided, the system allocates +enough memory to handle an amount of swap +that corresponds to eight times the amount of +physical memory present in the system. +.Pp +Note that swap metadata can be fragmented, +which means that the system can run out of +space before it reaches the theoretical limit. +Therefore, care should be taken to not configure +more swap than approximately half of the +theoretical maximum. +.Pp +Running out of space for swap metadata can leave +the system in an unrecoverable state. +Therefore, you should only change this parameter if you need to greatly extend the KVM reservation for other resources such as the buffer cache or Modified: head/sys/i386/include/param.h ============================================================================== --- head/sys/i386/include/param.h Tue Aug 14 14:07:34 2012 (r239254) +++ head/sys/i386/include/param.h Tue Aug 14 17:01:21 2012 (r239255) @@ -123,14 +123,6 @@ #define KSTACK_GUARD_PAGES 1 /* pages of kstack guard; 0 disables */ /* - * Ceiling on amount of swblock kva space, can be changed via - * the kern.maxswzone /boot/loader.conf variable. - */ -#ifndef VM_SWZONE_SIZE_MAX -#define VM_SWZONE_SIZE_MAX (32 * 1024 * 1024) -#endif - -/* * Ceiling on size of buffer cache (really only effects write queueing, * the VM page cache is not effected), can be changed via * the kern.maxbcache /boot/loader.conf variable.