From owner-freebsd-hackers Mon Oct 23 13: 5: 3 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from mass.osd.bsdi.com (adsl-63-202-176-145.dsl.snfc21.pacbell.net [63.202.176.145]) by hub.freebsd.org (Postfix) with ESMTP id 991F337B4CF for ; Mon, 23 Oct 2000 13:05:00 -0700 (PDT) Received: from mass.osd.bsdi.com (localhost [127.0.0.1]) by mass.osd.bsdi.com (8.11.0/8.9.3) with ESMTP id e9NK7Ih04538; Mon, 23 Oct 2000 13:07:21 -0700 (PDT) (envelope-from msmith@mass.osd.bsdi.com) Message-Id: <200010232007.e9NK7Ih04538@mass.osd.bsdi.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: "Christopher Harrer" Cc: "Freebsd-Hackers" Subject: Re: Cache Questions In-reply-to: Your message of "Mon, 23 Oct 2000 08:33:04 EDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 23 Oct 2000 13:07:18 -0700 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Hello All, > > We're working on a driver for a PCI card, we're currently running into a > problem that's symptomatic of a cache coherency problem. We have a area of > memory that we manipulate and pass a physical address to our card. In other > OS's (Linux, NT), before we manipulate this memory area, we mark the area as > non-cachable. Are there similar operations/system calls we can use in > FreeBSD? Are there any FAQ's, Docs or man-pages that explain memory > usage/attributes? Take a look at , and particularly mem_range_attr_set(). *However*, since the PC architecture is strongly cache coherent, you probably have a problem with the design or implementation of your driver:adapter protocol. Marking an entire region of memory as uncacheable is *very* inefficient; there are much better ways of maintaining synchronisation without doing this. -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] V I C T O R Y N O T V E N G E A N C E To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message