From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16648 invoked by alias); 22 Jul 2011 16:53:15 -0000 Received: (qmail 16639 invoked by uid 22791); 22 Jul 2011 16:53:14 -0000 X-SWARE-Spam-Status: No, hits=-2.6 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (74.125.121.67) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 22 Jul 2011 16:52:59 +0000 Received: from kpbe20.cbf.corp.google.com (kpbe20.cbf.corp.google.com [172.25.105.84]) by smtp-out.google.com with ESMTP id p6MGqttu010247 for ; Fri, 22 Jul 2011 09:52:56 -0700 Received: from gyh3 (gyh3.prod.google.com [10.243.50.195]) by kpbe20.cbf.corp.google.com with ESMTP id p6MGpSnl026440 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Fri, 22 Jul 2011 09:52:54 -0700 Received: by gyh3 with SMTP id 3so1696861gyh.33 for ; Fri, 22 Jul 2011 09:52:53 -0700 (PDT) Received: by 10.151.40.21 with SMTP id s21mr2089528ybj.430.1311353572146; Fri, 22 Jul 2011 09:52:52 -0700 (PDT) MIME-Version: 1.0 Received: by 10.151.48.15 with HTTP; Fri, 22 Jul 2011 09:52:21 -0700 (PDT) In-Reply-To: <20110722164341.GC5177@adacore.com> References: <20110715180748.A0390190BC2@elbrus2.mtv.corp.google.com> <20110722164341.GC5177@adacore.com> From: Paul Pluzhnikov Date: Fri, 22 Jul 2011 17:01:00 -0000 Message-ID: Subject: Re: [RFC] Make target_read_string faster over high-latency links. To: Joel Brobecker Cc: Tom Tromey , gdb-patches@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-System-Of-Record: true X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-07/txt/msg00627.txt.bz2 On Fri, Jul 22, 2011 at 9:43 AM, Joel Brobecker wro= te: >> Paul> 1. is it ok to read strings 128 bytes at a time, or are there >> Paul> scenarios (JTAG?) where the latency is low but throughput is also >> Paul> low (and so reading "unnecessary" data is expensive) ? >> >> I don't know, but I assume so. > > I think that the risk is to attempt a read that gets past the > readable memory region. That shouldn't be a risk (I think): target_read will (is supposed to) return partial results. >> What about making it possible for gdbserver to do the string-reading >> itself, with a fallback to the existing code for older versions? =A0Then >> you don't need a parameter or any tuning. > > Seems like a good idea to me. FWIW, additional discussion here: http://sourceware.org/ml/gdb-patches/2011-07/msg00546.html --=20 Paul Pluzhnikov