From owner-freebsd-stable@FreeBSD.ORG Mon Jun 9 01:55:04 2003 Return-Path: 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 A563B37B401 for ; Mon, 9 Jun 2003 01:55:04 -0700 (PDT) Received: from HAL9000.homeunix.com (ip114.bella-vista.sfo.interquest.net [66.199.86.114]) by mx1.FreeBSD.org (Postfix) with ESMTP id EDECA43FDD for ; Mon, 9 Jun 2003 01:55:03 -0700 (PDT) (envelope-from das@freebsd.org) Received: from HAL9000.homeunix.com (localhost [127.0.0.1]) by HAL9000.homeunix.com (8.12.9/8.12.9) with ESMTP id h598ssPB005689; Mon, 9 Jun 2003 01:54:54 -0700 (PDT) (envelope-from das@freebsd.org) Received: (from das@localhost) by HAL9000.homeunix.com (8.12.9/8.12.9/Submit) id h598ssMk005688; Mon, 9 Jun 2003 01:54:54 -0700 (PDT) (envelope-from das@freebsd.org) Date: Mon, 9 Jun 2003 01:54:54 -0700 From: David Schultz To: Masachika ISHIZUKA Message-ID: <20030609085454.GA5633@HAL9000.homeunix.com> Mail-Followup-To: Masachika ISHIZUKA , stable@freebsd.org References: <200305280102.LAA00949@lightning.itga.com.au> <20030609.114033.74731601.ishizuka@ish.org> <20030609041942.GA4029@HAL9000.homeunix.com> <20030609.163252.71109503.ishizuka@ish.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030609.163252.71109503.ishizuka@ish.org> cc: stable@freebsd.org Subject: Re: system slowdown - vnode related X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Jun 2003 08:55:04 -0000 On Mon, Jun 09, 2003, Masachika ISHIZUKA wrote: > >> I have still vnodes problem in 4.8-stable with /sys/kern/vfs_subr.c > >> 1.249.2.30. > >> > >> (1) #1 machine (Celeron 466 with 256 mega byte rams) > >> > >> % sysctl kern.maxvnodes > >> kern.maxvnodes: 17979 > >> % sysctl vm.zone | grep VNODE > >> VNODE: 192, 0, 18004, 122, 18004 > > > > This looks pretty normal to me for a quiescent system. > > Hi, David-san. > Thank you for mail. > I think the used(18004) exceeds maxvnodes(17979), isn't it ? Only by a little bit. maxvnodes isn't a hard limit, since making it a hard limit would lead to deadlocks. Instead, the system garbage collects vnodes to keep the number roughly in line with maxvnodes. Judging by the numbers above, it's doing a pretty good job, but that's probably because, from the looks of it, you just booted the system. The reason it might make sense to increase maxvnodes is that having vnlru work overtime to keep your vnode count low may result in vnodes being freed that are still needed, e.g. by the buffer cache. This would cause the slowdown you were mentioning. (As a disclaimer, Tor Egge and Matt Dillon know far more about this than I do.) > > I would actually suggest raising maxvnodes if you have lots of > > little files. Does the number of vnodes shoot up when 310.locate > > runs? > > The value shown above is the value at slow down time of 310.locate. > The number of used vnodes is low at boot up until 310.locate invoked. > > > Did you get a backtrace from the panics? > > It's too hard for me. Is there any way to do it ? The panics might be unrelated to the number of vnodes, so it's important that we have additional information. See: http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html