Date: Wed, 19 Sep 2007 18:45:27 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: Bruce Evans <brde@optusnet.com.au> Cc: arch@freebsd.org Subject: Re: 64bit ticks, was Re: Changing p_swtime and td_slptime to ticks Message-ID: <20070919084527.GA1179@turion.vk2pj.dyndns.org> In-Reply-To: <20070919133525.E78370@besplex.bde.org> References: <20070917165657.B558@10.0.0.1> <46EF644E.9050207@elischer.org> <20070918012555.G558@10.0.0.1> <46EFE4BD.4030505@freebsd.org> <20070918142115.C558@10.0.0.1> <20070918153536.D558@10.0.0.1> <46F05F88.5060809@errno.com> <46F0656A.7030802@elischer.org> <20070919133525.E78370@besplex.bde.org>
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--82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2007-Sep-19 14:55:35 +1000, Bruce Evans <brde@optusnet.com.au> wrote: >I agree. However, one variable isn't going to make much difference. fs >code is full of unecessary 64-bit calculations but no one notices the >real-time pessimization from this, at least on non-low-end platforms (I >only notice the code bloat). I suspect the pessimization from the 64-bit arithmetic is masked by the requirement that the FS code talk to (mostly rotating) media. The cost of an extra couple of instructions gets lost in the noise as soon as you look at disk latencies. --=20 Peter Jeremy --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFG8OGn/opHv/APuIcRAnsaAKCBMga+Z1YF6FyszCzJEMsq7WxUUgCgn8WF ZMYy8zEUPnljXr43y3PpNRc= =4kon -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs--
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