From owner-freebsd-arch  Mon Feb  5 14:39: 9 2001
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To: "Justin T. Gibbs" <gibbs@scsiguy.com>
Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>,
	Alfred Perlstein <bright@wintelcom.net>,
	Randell Jesup <rjesup@wgate.com>,
	Matt Dillon <dillon@earth.backplane.com>,
	Matthew Jacob <mjacob@feral.com>, Mike Smith <msmith@FreeBSD.ORG>,
	Dag-Erling Smorgrav <des@ofug.org>,
	Dan Nelson <dnelson@emsphone.com>,
	Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>, arch@FreeBSD.ORG
Subject: Re: Bumping up {MAX,DFLT}*PHYS (was Re: Bumping up {MAX,DFL}*SIZ in i386) 
In-reply-to: Your message of "Mon, 05 Feb 2001 15:24:02 MST."
             <200102052224.f15MO2O51248@aslan.scsiguy.com> 
From: Chuck Paterson <cp@bsdi.com>
Date: Mon, 05 Feb 2001 15:34:41 -0700
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	In the discussions I noticed someone mentioned some
of the issues with architectures like Sparc. I haven't noticed
anyone discuss the need to deal with the limited DVMA space. You
really need to have some reservation policy on the buffer before
you send them down to a driver, or at least have the
driver do a call to get a reservatioin commitment before
actually doing the map ins. If not you could have problems
like two drivers trying to map there io buffer, both having them
half mapped and unable to get the resouces to finish the mapping.

Chuck
Chuck


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