From owner-freebsd-arch Tue Feb 19 9:55: 4 2002 Delivered-To: freebsd-arch@freebsd.org Received: from eumenes.hosting.pacbell.net (eumenes.hosting.pacbell.net [216.100.98.24]) by hub.freebsd.org (Postfix) with ESMTP id 3CE4E37B402; Tue, 19 Feb 2002 09:54:55 -0800 (PST) Received: from misha1 (adsl-64-172-38-74.dsl.snfc21.pacbell.net [64.172.38.74]) by eumenes.hosting.pacbell.net id MAA13437; Tue, 19 Feb 2002 12:54:52 -0500 (EST) [ConcentricHost SMTP Relay 1.14] Message-ID: <004f01c1b96b$a37d1f50$b210a8c0@netscreen5> Reply-To: "mike varga" From: "mike varga" To: "Michael Smith" Cc: References: <200202170813.g1H8DAV01750@mass.dis.org> Subject: Re: reverse vtophys() Date: Tue, 19 Feb 2002 09:34:04 -0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 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 The concept is valid in Linux, there is a function that does what I am asking. bus_to_virtual(). The page is locked in memory. Therefor there is one valid page backed by the physical address that corresponds to the virtual address that I am interested in retrieving? ----- Original Message ----- From: "Michael Smith" To: "mike varga" Cc: Sent: Sunday, February 17, 2002 12:13 AM Subject: Re: reverse vtophys() > > > > Is there a function that exists=20 > > that converts a physical address to=20 > > a process's virtual address? > > No; the concept isn't valid. > > - A given physical address may be mapped in more than one virtual > location within the process' address space. > > - There is an unavoidable race with unwired memory where a physical > page may "move" as it is used to back more than a single physical > page, resulting in a bad answer. > > Perhaps you should explain what it is that you're trying to do, rather > than narrowing down to what you think is the solution... > > -- > To announce that there must be no criticism of the president, > or that we are to stand by the president, right or wrong, is not > only unpatriotic and servile, but is morally treasonable to > the American public. - Theodore Roosevelt > > > > 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