From owner-freebsd-stable Sat Aug 31 13: 3:14 2002 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AC7B737B400; Sat, 31 Aug 2002 13:03:08 -0700 (PDT) Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 255FE43E6A; Sat, 31 Aug 2002 13:03:08 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: from apollo.backplane.com (localhost [127.0.0.1]) by apollo.backplane.com (8.12.5/8.12.4) with ESMTP id g7VK37PQ002118; Sat, 31 Aug 2002 13:03:07 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.12.5/8.12.4/Submit) id g7VK37aS002117; Sat, 31 Aug 2002 13:03:07 -0700 (PDT) (envelope-from dillon) Date: Sat, 31 Aug 2002 13:03:07 -0700 (PDT) From: Matthew Dillon Message-Id: <200208312003.g7VK37aS002117@apollo.backplane.com> To: "Marc G. Fournier" Cc: Arnvid Karstad , , Subject: Re: Problems with FreeBSD - causing zalloc to return 0 ?! References: <20020831140602.O14642-101000@mail1.hub.org> Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG : : This message is in MIME format. The first part should be readable text, : while the remaining parts are likely unreadable without MIME-aware tools. : Send mail to mime@docserver.cac.washington.edu for more info. : :--0-1838173444-1030814090=:14642 :Content-Type: TEXT/PLAIN; charset=US-ASCII : : :Morning ... as I said, shouldn't take long :) : :I setup the script to log in 1 second intervals, to a log.`date +%S` file, :hoping that you only wanted the last few seconds of data? If not, I can :set it up differently, but here are the result of the last minute of its :apparent existence ... : :First, the kernel panic of: Well Marc, there's nothing totally obvious here but it is still quite possible that the machine is running out of KVM. Try this. You can run gdb on a running machine as follows: gdb -k kernel.debug /dev/mem You can then print out elements of the kernel's memory in real time: gdb> print kernel_vm_end Could you post your kernel config? And repeat your test but run gdb in a shell and print kernel_vm_end at the start of your test and every so often while the test is running. Other things you can try that will reduce KVM usage: in /boot/loader.conf reduce the amount of physical memory, e.g. reduce from 4G to 2G with: hw.physmem="2048m" and see if you can repeat the problem. Oddly enough if you cannot repeat the problem the issue is almost certainly the kernel running out of KVM. You can also try reducing the number of mbuf clusters and reducing maxvnodes, though the values I saw in your logs seem reasonable. If you only have one swap device you can reducing the number of swap devices by setting the NSWAPDEV kernel config variable to 1 (it defaults to 4). This will reduce the KVM reservation for the swap bitmap. You can also reduce the kernel reservation for swap block data by setting the kern.maxswzone boot environment variable. This is in bytes, e.g. in /boot/loader.conf kern.maxswzone="32m" All of these ideas are designed to reduce KVM usage. I am extremely interested in knowing if they have an effect on the crashes you are seeing. If you can stop the crashes from occuring then we are going to have to get more conservative in our KVM allocations. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message