From owner-freebsd-net@FreeBSD.ORG Mon Apr 21 08:17:01 2008 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E05871065672; Mon, 21 Apr 2008 08:17:01 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from outbound0.mx.meer.net (outbound0.mx.meer.net [209.157.153.23]) by mx1.freebsd.org (Postfix) with ESMTP id BC48C8FC25; Mon, 21 Apr 2008 08:17:01 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from mail.meer.net (mail.meer.net [209.157.152.14]) by outbound0.mx.meer.net (8.12.10/8.12.6) with ESMTP id m3L8H0hs096252; Mon, 21 Apr 2008 01:17:01 -0700 (PDT) (envelope-from gnn@neville-neil.com) Received: from mail2.meer.net (mail2.meer.net [64.13.141.16]) by mail.meer.net (8.13.3/8.13.3/meer) with ESMTP id m3L8GUcV033985; Mon, 21 Apr 2008 01:16:30 -0700 (PDT) (envelope-from gnn@neville-neil.com) Received: from minion.local.neville-neil.com (61.204.211.246.customerlink.pwd.ne.jp [61.204.211.246]) (authenticated bits=0) by mail2.meer.net (8.14.1/8.14.1) with ESMTP id m3L8GTuR020588; Mon, 21 Apr 2008 01:16:30 -0700 (PDT) (envelope-from gnn@neville-neil.com) Date: Mon, 21 Apr 2008 17:16:28 +0900 Message-ID: From: gnn@freebsd.org To: gnn@freebsd.org In-Reply-To: References: <20080420102827.U67663@fledge.watson.org> User-Agent: Wanderlust/2.15.5 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL/10.7 Emacs/22.1.50 (i386-apple-darwin8.11.1) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: Robert Watson , net@freebsd.org Subject: Re: zonelimit issues... X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Apr 2008 08:17:02 -0000 At Mon, 21 Apr 2008 16:46:00 +0900, gnn@freebsd.org wrote: > > At Sun, 20 Apr 2008 10:32:25 +0100 (BST), > rwatson wrote: > > > > > > On Fri, 18 Apr 2008, gnn@freebsd.org wrote: > > > > > I am wondering why this patch was never committed? > > > > > > http://people.freebsd.org/~delphij/misc/patch-zonelimit-workaround > > > > > > It does seem to address an issue I'm seeing where processes get into the > > > zonelimit state through the use of mbufs (a high speed UDP packet receiver) > > > but even after network pressure is reduced/removed the process never gets > > > out of that state again. Applying the patch fixed the issue, but I'd like > > > to have some discussion as to the general merits of the approach. > > > > > > Unfortunately the test that currently causes this is tied very tightly to > > > code at work that I can't share, but I will hopefully be improving mctest to > > > try to exhibit this behavior. > > > > When you take all load off the system, do mbufs and clusters get properly > > freed back to UMA (as visible in netstat -m)? If not, continuing to bump up > > against the zonelimit would suggest an mbuf/cluster leak, in which case we > > need to track that bug. > > > > This is unclear as the process that creates the issue opens 50 UDP > multicast sockets with very large socket buffers. I am investigating > this aspect some more. > OK, yes, the clusters etc. go back to normal when the incoming pressure is released. I do not believe we have a cluster/mbuf leak. Best, George