From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23594 invoked by alias); 25 Jul 2011 19:00:31 -0000 Received: (qmail 23582 invoked by uid 22791); 25 Jul 2011 19:00:30 -0000 X-SWARE-Spam-Status: No, hits=-7.0 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, 25 Jul 2011 19:00:13 +0000 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6PJ0CIJ019628 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 25 Jul 2011 15:00:12 -0400 Received: from host1.jankratochvil.net (ovpn-116-20.ams2.redhat.com [10.36.116.20]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p6PJ0Aqw005788 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 25 Jul 2011 15:00:11 -0400 Received: from host1.jankratochvil.net (localhost [127.0.0.1]) by host1.jankratochvil.net (8.14.4/8.14.4) with ESMTP id p6PJ09oC031279; Mon, 25 Jul 2011 21:00:09 +0200 Received: (from jkratoch@localhost) by host1.jankratochvil.net (8.14.4/8.14.4/Submit) id p6PJ08n2031278; Mon, 25 Jul 2011 21:00:08 +0200 Date: Mon, 25 Jul 2011 19:26:00 -0000 From: Jan Kratochvil To: Paul Pluzhnikov Cc: gdb-patches@sourceware.org Subject: Re: [RFC][patch] Make DCACHE_LINE runtime-settable Message-ID: <20110725190008.GA30896@host1.jankratochvil.net> References: <20110722222025.ED9B6190B14@elbrus2.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110722222025.ED9B6190B14@elbrus2.mtv.corp.google.com> User-Agent: Mutt/1.5.21 (2010-09-15) 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/msg00704.txt.bz2 On Sat, 23 Jul 2011 00:20:25 +0200, Paul Pluzhnikov wrote: > For a 200ms round-trip connection, executing "where" and getting back 30 > frames translates into 6 seconds of wall time, and "thread apply all where" > into 1 to 10 to 100 minutes (depending on how many threads there are, > with 100 threads being common and 1000 not being exceptional). > > Attached patch allows the user to e.g. "set dcache-line-size 4096" and > drastically reduce the number of round trips. I was tweaking the LINE_SIZE_POWER facing this problem in mail: https://fedorahosted.org/pipermail/crash-catcher/2010-December/001441.html I have seen some of the target_read_memory requests are needlessly fragmented into LINE_SIZE_POWER sized read requests. Have you considered making the gdbserver protocol read requests size dynamic depending on the caller's requested read size? After all I found it is in many cases the fastest to upload the whole core file as then there are no RTT delays at all but that is offtopic here. Thanks, Jan