From owner-freebsd-current@FreeBSD.ORG Wed Dec 17 16:58:14 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7410516A4CE; Wed, 17 Dec 2003 16:58:14 -0800 (PST) Received: from carver.gumbysoft.com (carver.gumbysoft.com [66.220.23.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1A5E943D3F; Wed, 17 Dec 2003 16:58:09 -0800 (PST) (envelope-from dwhite@gumbysoft.com) Received: by carver.gumbysoft.com (Postfix, from userid 1000) id 0F14372DB5; Wed, 17 Dec 2003 16:58:09 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by carver.gumbysoft.com (Postfix) with ESMTP id 0A08572DAD; Wed, 17 Dec 2003 16:58:09 -0800 (PST) Date: Wed, 17 Dec 2003 16:58:09 -0800 (PST) From: Doug White To: =?gb2312?B?WGluIExJL8Du9s4=?= In-Reply-To: <20031218004038.B3EE45302@ftp.bjpu.edu.cn> Message-ID: <20031217165012.K15803@carver.gumbysoft.com> References: <20031218004038.B3EE45302@ftp.bjpu.edu.cn> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=gb2312 Content-Transfer-Encoding: QUOTED-PRINTABLE cc: stable@FreeBSD.org cc: current@freebsd.org Subject: Re: [Backtrace] 4.9 and 5.1-RELEASE occasionly panic on RAM > 4GB without PAE (long) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Dec 2003 00:58:14 -0000 On Thu, 18 Dec 2003, [gb2312] Xin LI/=C0=EE=F6=CE wrote: > One of my friend is operating servers on a big ICP in China. They found t= hat > if they run FreeBSD 4.9 or FreeBSD 5.1-RELEASE on their server, which has > more than 4GB RAM installed, then they will occasionaly have the server > panic'ed, or even rebooted without any reason. > > The server hardware is: P4-Xeon-2.4G*2, 4G RAM(DDR266), 146G*2 on asr(4) > RAID-1. The kernel is not quite different from GENERIC, except that we ha= ve > AUTO_EOI1 enabled. When PAE is enabled, then the kernel will not recogniz= e > the asr(4) device, and thus would refuse to boot from it, so we have it > disabled. PAE only has effect for >4GB (strictly), so exactly 4GB will work fine with !PAE. > This problem afffects 4.9-RELEASE and 5.1-RELEASE. As the ICP is a > conservative user, they will not run -STABLE, nor -CURRENT. I have turned > the debugging symbols on their server and grabbed the following backtrace= s. > Also, I have found how to reproduce this problem on a machine running wit= h > > 4GB memory without a PAE configuration, which, in my opinion, should not > cause a kernel panic because it's just a resource hungry program and all = it > will do should, at most, hang the system, or even being killed directly b= y > the operating system. Its probably due to poor tuning in this case. See the tuning(7) man page and innumerable mailing lists posts. Basically, you want to turn down maxusers (128 or so works best) and maybe change the kernel/user boundary and kmem sizes. vmstat -m is useful to keep track of kernel memory use. Also forkbombs (which is what your program is, effectively) are best controlled by using user resource limits. They're there for a reason. See the login.conf(5) man page. > panic: pmap_new_proc: u_map allocation failed kmem exhaustion condition in -stable. --=20 Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org