From owner-freebsd-stable Wed Sep 4 15:11: 7 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 384E837B496 for ; Wed, 4 Sep 2002 15:11:01 -0700 (PDT) Received: from host217-41-4-70.in-addr.btopenworld.com (host217-41-4-70.in-addr.btopenworld.com [217.41.4.70]) by mx1.FreeBSD.org (Postfix) with ESMTP id AFF1E43E42 for ; Wed, 4 Sep 2002 15:10:59 -0700 (PDT) (envelope-from dom@host217-41-4-70.in-addr.btopenworld.com) Received: by host217-41-4-70.in-addr.btopenworld.com (Postfix, from userid 1001) id 3BBDD1EE; Wed, 4 Sep 2002 23:11:08 +0100 (BST) Date: Wed, 4 Sep 2002 23:11:08 +0100 From: Dominic Marks To: Dmitry Morozovsky Cc: Mike Hoskins , Charles Sprickman , stable@FreeBSD.ORG Subject: Re: interpreting netstat -m output Message-ID: <20020904221108.GA1879@gallium> References: <20020904212032.GA1688@gallium> <20020905014934.J56943-100000@woozle.rinet.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020905014934.J56943-100000@woozle.rinet.ru> User-Agent: Mutt/1.5.1i 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 On Thu, Sep 05, 2002 at 02:04:05AM +0400, Dmitry Morozovsky wrote: > On Wed, 4 Sep 2002, Dominic Marks wrote: > > DM> An mbuf is a fixed length structure which contains network data. > DM> > DM> An mbuf cluster is associated with an area of memory which is used for > DM> storing more data than you can fit in a single mbuf. > DM> > DM> According the D&I 4.4 an mbuf is 128 bytes and (not all of this is > DM> available for data storage), an mbuf cluster varies in size, but > DM> defaults to 1024 bytes (but according to the book this may be different > DM> depending on CPU architecture). > > AFAIK according to /usr/src/sys/*/param.h, mbuf size if 256 (at least for > i386, see /usr/src/sys/i386/include/param.h, and is not defined for > Alphas); > > and mbcluster size defaults to 2k (I suppose the smallest 2^x to > cover standard Ethernet frame) > > however, in /usr/src/sys/i386/boot/dosboot/param.h, MCLBYTES defined as > 2^12 (4k). Don't know whether this value is really used. I would not be surprised to find that these are the current values. I quoted directly from the book which is a bit old. > Sincerely, > D.Marck [DM5020, DM268-RIPE, DM3-RIPN] > ------------------------------------------------------------------------ > *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru *** > ------------------------------------------------------------------------ > -- Dominic Marks Computer & Politics Geek [work]::[npl.co.uk] << dominic.marks at npl.co.uk >> [educ]::[umist.ac.uk] << notyet-known at umist.ac.uk >> [home]::[btinternet] << dominic_marks at btinternet.com >> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message