From owner-freebsd-current@FreeBSD.ORG Mon Jul 31 19:12:11 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B755016A4E1; Mon, 31 Jul 2006 19:12:11 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail11.syd.optusnet.com.au (mail11.syd.optusnet.com.au [211.29.132.192]) by mx1.FreeBSD.org (Postfix) with ESMTP id B5DF643D6D; Mon, 31 Jul 2006 19:12:09 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail11.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k6VJC7Jw016454 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Tue, 1 Aug 2006 05:12:08 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.6/8.13.6) with ESMTP id k6VJC67e005190; Tue, 1 Aug 2006 05:12:06 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.6/8.13.6/Submit) id k6VJC6KG005189; Tue, 1 Aug 2006 05:12:06 +1000 (EST) (envelope-from peter) Date: Tue, 1 Aug 2006 05:12:06 +1000 From: Peter Jeremy To: John Baldwin Message-ID: <20060731191206.GE749@turion.vk2pj.dyndns.org> References: <200607251254.k6PCsBef092737@lurza.secnetix.de> <20060728134701.GA45273@uk.tiscali.com> <20060728210154.GC748@turion.vk2pj.dyndns.org> <200607311437.57273.jhb@freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Rgf3q3z9SdmXC6oT" Content-Disposition: inline In-Reply-To: <200607311437.57273.jhb@freebsd.org> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.11 Cc: freebsd-current@freebsd.org Subject: Re: vmstat's entries type X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Mon, 31 Jul 2006 19:12:11 -0000 --Rgf3q3z9SdmXC6oT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, 2006-Jul-31 14:37:56 -0400, John Baldwin wrote: >On Friday 28 July 2006 17:01, Peter Jeremy wrote: >> This approach still requires the reader to loop with something like >> do { >> a.lo =3D counter.lo; >> a.hi =3D counter.hi; >> b.lo =3D counter.lo; >> b.hi =3D counter.hi; >> } while (a.hi !=3D b.hi || a.lo > b.lo); >> to ensure that the reader doesn't read the middle of an update. > >Yes, but the idea here is that these stats are written to far more often t= han=20 >read, so it's ok to pessimize the read case. We are in violent agreement here. My point was that the reader has to be aware of this requirement. --=20 Peter Jeremy --Rgf3q3z9SdmXC6oT Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.4 (FreeBSD) iD8DBQFEzlYG/opHv/APuIcRAs3zAJwIm4E1vcj9KcBtgMswGbZvi9XzEwCgpWWH NU5HOWWSUlt4vAnSSLKS4lY= =CJyo -----END PGP SIGNATURE----- --Rgf3q3z9SdmXC6oT--