From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28975 invoked by alias); 23 Jun 2003 20:11:30 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 10169 invoked from network); 23 Jun 2003 19:59:56 -0000 Received: from unknown (HELO netezza.com) (209.113.240.37) by sources.redhat.com with SMTP; 23 Jun 2003 19:59:56 -0000 Received: from astral (host20 [192.168.0.20]) by netezza.com (8.12.9+Sun/8.12.9) with SMTP id h5NJxtgv003206 for ; Mon, 23 Jun 2003 15:59:55 -0400 (EDT) Message-ID: <03f001c339c2$047745b0$1400a8c0@astral> Reply-To: "John S. Yates, Jr." From: "John S. Yates, Jr." To: References: <1056381193.18735.ezmlm@sources.redhat.com> Subject: Re: Always cache memory and registers Date: Mon, 23 Jun 2003 20:11:00 -0000 Organization: Netezza Corporation MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-SW-Source: 2003-06/txt/msg00464.txt.bz2 ----- Original Message ----- From: Andrew Cagney Sent: Sun, 22 Jun 2003 18:26:13 -0400 > The only proviso being that the current cache and > target vector would need to be modified so that the > cache only ever requested the data needed, leaving it > to the target to supply more if available (much like > registers do today). The current dcache doesn't do > this, it instead pads out small reads :-( How much freedom would the target have? If a random byte in the middle of a cache-line was requested could a target back up the starting address to the beginning of the cache-line? What happens if host requests byte at address X and target returns data from range Y to Z where X does not fall within that range? (Suggestion: host places returned data in cache and reattempts the access; this will lead to a request of X from the target; presumably the target has its own rationale for why it is returning unrequested data and will eventually return the request byte; at that point the host cache access will succeed returning the request byte to its caller.) /john -- John S. Yates, Jr. 508 665-6897 (voice) Netezza Inc 508 665-6811 (fax) 200 Crossing Blvd. Framingham, MA 01701