From owner-freebsd-arch Wed Mar 21 19:58:47 2001 Delivered-To: freebsd-arch@freebsd.org Received: from InterJet.elischer.org (c421509-a.pinol1.sfba.home.com [24.7.86.9]) by hub.freebsd.org (Postfix) with ESMTP id 0C0CF37B71B; Wed, 21 Mar 2001 19:58:45 -0800 (PST) (envelope-from julian@elischer.org) Received: from InterJet.elischer.org (InterJet.elischer.org [192.168.1.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id UAA11598; Wed, 21 Mar 2001 20:00:51 -0800 (PST) Date: Wed, 21 Mar 2001 20:00:50 -0800 (PST) From: Julian Elischer To: Matt Dillon Cc: Poul-Henning Kamp , Mike Smith , arch@FreeBSD.ORG Subject: Re: remind me again, why is MAXPHYS only 128k ? In-Reply-To: <200103212215.f2LMFig23991@earth.backplane.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG it has always been my opinion that the kernel should only handle physical pages for these sorts of things and any device drive should convert to virtual if it needs it. 'buffers' should be stored as a list of physical pages, and that list could be used directly by IO routines wishing to queue IO on the buffer. similarly Physio should produce a list of physical pages instead of a kvm pointer. Physio can certainly mallooc such a physical list. (one needs to bear in mind aio in this discussion.) On Wed, 21 Mar 2001, Matt Dillon wrote: > Another possibility for physio would be to MALLOC the pages > array at the very top level of the syscall and pass it down > through for use by lower layers. At the very top level, > before anything is locked, the MALLOC can block safely. > > -Matt > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-arch" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message