From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6507 invoked by alias); 18 Jul 2011 17:09:25 -0000 Received: (qmail 6497 invoked by uid 22791); 18 Jul 2011 17:09:24 -0000 X-SWARE-Spam-Status: No, hits=-7.4 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 18 Jul 2011 17:09:07 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6IH9524024126 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 18 Jul 2011 13:09:05 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p6IH94XG006510; Mon, 18 Jul 2011 13:09:05 -0400 Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p6IH93At016077; Mon, 18 Jul 2011 13:09:04 -0400 From: Tom Tromey To: ppluzhnikov@google.com (Paul Pluzhnikov) Cc: gdb-patches@sourceware.org Subject: Re: [RFC] Make target_read_string faster over high-latency links. References: <20110715180748.A0390190BC2@elbrus2.mtv.corp.google.com> Date: Mon, 18 Jul 2011 18:06:00 -0000 In-Reply-To: <20110715180748.A0390190BC2@elbrus2.mtv.corp.google.com> (Paul Pluzhnikov's message of "Fri, 15 Jul 2011 11:07:48 -0700 (PDT)") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain 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/msg00427.txt.bz2 >>>>> "Paul" == Paul Pluzhnikov writes: 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. Paul> 1a. If yes, would it be acceptable to make this size a Paul> runtime-configurable parameter? Yes. Paul> 2. Current target_read_string aligns reads on a 4-byte boundary. Code Paul> could be simplified quite a bit if it didn't do that. Paul> Are there targets where such alignment is required? I don't know this either, sorry. What about making it possible for gdbserver to do the string-reading itself, with a fallback to the existing code for older versions? Then you don't need a parameter or any tuning. Tom