From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6676 invoked by alias); 3 Jan 2011 23:47:28 -0000 Received: (qmail 6668 invoked by uid 22791); 3 Jan 2011 23:47:28 -0000 X-SWARE-Spam-Status: No, hits=-2.3 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_LOW,SPF_HELO_PASS,TW_BJ,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.44.51) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 03 Jan 2011 23:47:24 +0000 Received: from wpaz13.hot.corp.google.com (wpaz13.hot.corp.google.com [172.24.198.77]) by smtp-out.google.com with ESMTP id p03NlM2k013824 for ; Mon, 3 Jan 2011 15:47:22 -0800 Received: from qyj19 (qyj19.prod.google.com [10.241.83.83]) by wpaz13.hot.corp.google.com with ESMTP id p03NlIX4028691 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NOT) for ; Mon, 3 Jan 2011 15:47:21 -0800 Received: by qyj19 with SMTP id 19so13703605qyj.17 for ; Mon, 03 Jan 2011 15:47:20 -0800 (PST) Received: by 10.224.28.212 with SMTP id n20mr20076185qac.181.1294098440772; Mon, 03 Jan 2011 15:47:20 -0800 (PST) MIME-Version: 1.0 Received: by 10.220.7.132 with HTTP; Mon, 3 Jan 2011 15:46:50 -0800 (PST) In-Reply-To: <201101032332.28548.pedro@codesourcery.com> References: <201101032332.28548.pedro@codesourcery.com> From: Paul Pluzhnikov Date: Mon, 03 Jan 2011 23:47:00 -0000 Message-ID: Subject: Re: JIT interface slowness To: Pedro Alves Cc: Vyacheslav Egorov , gdb@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-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2011-01/txt/msg00011.txt.bz2 On Mon, Jan 3, 2011 at 3:32 PM, Pedro Alves wrote: > gdb.base/ should be fine. > gdb.gdb/ is for tests that load gdb itself as an inferior. Ah, thanks. >> diff -u -r1.8 jit.c > > Please use cvs diff -up. =A0-p makes wonders at making > patches easier to read. Sorry about that. It's been a long time since I sent patches, got rusty :-( >> I think it's pretty safe to assume that we don't need to search JITted >> objfiles for above functions, as JITs do not participate in normal symbol >> resolution at all. > > But doesn't that mean that pending breakpoints on JITed functions > won't resolve anymore? Right. >> Do we need a new OBJF_JIT flag, or is above patch good enough? > > What if we record a per-objfile flag or cache storing whether a given > objfile contains "longjmp" related symbols, so that we only lookup > those symbols at least once per DSO? Did you mean "at most once per DSO"? > Quite similar in spirit to > your objc_objfile_data change. =A0Do we still get a significant > slowdown from breakpoint_re_set with that change? We probably wouldn't. I'll make a proper patch, measure, and send to gdb-patches. > (I've also noticed before that lookup_minimal_symbol_text iterates > over all objfiles even if given an objfile to work with (worse > case, but then again, new objfiles are appended at the end > of the objfile list). =A0Probably contributes to the noise, but > these things add up.) I'll fix that as well. Thanks for comments! --=20 Paul Pluzhnikov