From owner-freebsd-arch Wed Feb 13 17:15:25 2002 Delivered-To: freebsd-arch@freebsd.org Received: from hawk.mail.pas.earthlink.net (hawk.mail.pas.earthlink.net [207.217.120.22]) by hub.freebsd.org (Postfix) with ESMTP id 98B2337B405; Wed, 13 Feb 2002 17:15:22 -0800 (PST) Received: from pool0388.cvx40-bradley.dialup.earthlink.net ([216.244.43.133] helo=mindspring.com) by hawk.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 16bAUb-0005B5-00; Wed, 13 Feb 2002 17:15:21 -0800 Message-ID: <3C6B0F9F.BC4C102E@mindspring.com> Date: Wed, 13 Feb 2002 17:15:11 -0800 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Michael Smith Cc: mike varga , Steve Kargl , freebsd-arch@freebsd.org Subject: Re: bus_dma_load_uio() function References: <200202131847.g1DIlwg01147@mass.dis.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Michael Smith wrote: > > It removes unnecessary > > copies. > > Typically, you let the kernel do this for you, via the physio interface. Mike's particular use would see any paging as a very big stall. Locking down mappings vs. wiring down pages pretty much wants the pages to be in the KVA space and mapped into the process, instead of vice-versa. His repsonse requirements are very similar to those of a video capture card. PS: Mike: make sure it generates interrupts; see Luigi Rizzo's current work with polling: even with polling, the trigger is an interrupt. ;^). -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message