From owner-freebsd-current@FreeBSD.ORG Thu Oct 28 04:53:27 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from green.homeunix.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 06CAD16A4CE; Thu, 28 Oct 2004 04:53:27 +0000 (GMT) Received: from green.homeunix.org (green@localhost [127.0.0.1]) by green.homeunix.org (8.13.1/8.13.1) with ESMTP id i9S4rQcN010362; Thu, 28 Oct 2004 00:53:26 -0400 (EDT) (envelope-from green@green.homeunix.org) Received: (from green@localhost) by green.homeunix.org (8.13.1/8.13.1/Submit) id i9S4rPOO010361; Thu, 28 Oct 2004 00:53:25 -0400 (EDT) (envelope-from green) Date: Thu, 28 Oct 2004 00:53:24 -0400 From: Brian Fundakowski Feldman To: Andrew Gallatin Message-ID: <20041028045324.GJ93831@green.homeunix.org> References: <16757.36934.576905.271257@grasshopper.cs.duke.edu> <16757.37685.44641.533455@grasshopper.cs.duke.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16757.37685.44641.533455@grasshopper.cs.duke.edu> User-Agent: Mutt/1.5.6i cc: freebsd-current@freebsd.org cc: Robert Watson Subject: Re: mbuf leak with SMP and debug.mpsafenet=1 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, 28 Oct 2004 04:53:27 -0000 On Tue, Oct 19, 2004 at 06:20:37PM -0400, Andrew Gallatin wrote: > > Robert Watson writes: > > > > Yeah -- I've been trying to avoid committing this patch since atomic > > operations hurt the P4 quite a bit more than one would hope. We already > > do MPSAFE stats in UMA, so an interesting question might be whether these > > stats are redundant to stats already gathered and we can use them instead. > > One of the theoretical advantages of mbuma is that mbufs become just > > another case of existing slab allocated memory resources, so I would think > > most of the interesting stats should be there. > > Getting the stats from uma seems like the right thing to do in the > long run, but the atomic stats is a low-risk way to avoid bogus > mbuf leak reports from 5.3-RELEASE users. I ran into this last week and kept wondering how I was losing so many mbufs, then searching the kernel for possible scenarios... finding none finally matching up vmstat -z output with netstat -m to clue myself in. We could really easily just add to netstat -m warnx("value for SMP systems may be misleading; see manpage"); -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\