Date: Tue, 1 Aug 2006 05:12:06 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: vmstat's entries type Message-ID: <20060731191206.GE749@turion.vk2pj.dyndns.org> In-Reply-To: <200607311437.57273.jhb@freebsd.org> References: <200607251254.k6PCsBef092737@lurza.secnetix.de> <20060728134701.GA45273@uk.tiscali.com> <20060728210154.GC748@turion.vk2pj.dyndns.org> <200607311437.57273.jhb@freebsd.org>
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--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--
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