From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21704 invoked by alias); 31 Oct 2003 23:42:58 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 21697 invoked from network); 31 Oct 2003 23:42:57 -0000 Received: from unknown (HELO localhost.redhat.com) (207.219.125.105) by sources.redhat.com with SMTP; 31 Oct 2003 23:42:57 -0000 Received: from redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id ECB792B89; Fri, 31 Oct 2003 18:42:54 -0500 (EST) Message-ID: <3FA2F37E.1020108@redhat.com> Date: Fri, 31 Oct 2003 23:42:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030820 X-Accept-Language: en-us, en MIME-Version: 1.0 To: davidm@hpl.hp.com, Marcel Moolenaar Cc: "J. Johnston" , gdb-patches@sources.redhat.com, Kevin Buettner Subject: Re: RFA: ia64 portion of libunwind patch References: <3FA2B71A.3080905@redhat.com> <20031031213551.GA67387@dhcp01.pn.xcllnt.net> <16290.59792.76966.437973@napali.hpl.hp.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-10/txt/msg00899.txt.bz2 > On Fri, 31 Oct 2003 13:35:51 -0800, Marcel Moolenaar said: > > > Marcel> Since libunwind already does its own caching, we may be > Marcel> better off not caching in gdb. > > That's true. However, note that by default, caching is not enabled > for remote unwinding (which is what gdb does). To enable caching, gdb > would have to make a call of the form: > > unw_set_caching_policy(ADDR_SPACE, UNW_CACHE_GLOBAL); > > Also, whenever something changes in the target that could invalidate > cached unwind info, gdb would have to call: > > unw_flush_cache(ADDR_SPACE, LO, HI); > where LO and HI is the address range that was affected (or LO=0, HI=0 > to flush the entire cache). Just FYI, for GDB, it will be better to let the target stack to do the cache management. That way the user can set/override the policy. For instance, in the case in question, the user would be inane to specify anything other than: (gdb) set trust-readonly-sections 1 (which causes all read-only reads to be handled locally) this is also why the issue isn't really that much of a problem. Andrew