From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11535 invoked by alias); 15 Dec 2011 15:55:01 -0000 Received: (qmail 11493 invoked by uid 22791); 15 Dec 2011 15:55:00 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO sourceware.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 15 Dec 2011 15:54:45 +0000 From: "l.lunak at suse dot cz" To: gdb-prs@sourceware.org Subject: [Bug gdb/13498] save-index makes gdb slow with dwarf4 Date: Thu, 15 Dec 2011 15:55:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: gdb X-Bugzilla-Keywords: X-Bugzilla-Severity: minor X-Bugzilla-Who: l.lunak at suse dot cz X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Mailing-List: contact gdb-prs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-prs-owner@sourceware.org X-SW-Source: 2011-q4/txt/msg00526.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=3D13498 --- Comment #2 from Lubo=C5=A1 Lu=C5=88=C3=A1k 201= 1-12-15 15:54:43 UTC --- It takes so long because dw2_map_symbol_filenames() loops over both dwarf2_per_objfile::all_comp_units and dwarf2_per_objfile::type_comp_units, where e.g. LibreOffice's libswlo.so has ~700 of the first and ~16000 of the second. It appears unnecessary to iterate over type_comp_units, as all_comp_units should already include all the files encountered during compilation. But it turns out gdb performs poorly with DWARF4 in general. In this case dw2_map_symbol_filenames() could be fixed, assuming what I wrote above is correct, but there appear to be other inefficiencies (related to .debug_typ= es too?). E.g. 'break shared' (trying to complete a filename) is very fast with DWARF2, but takes very long with DWARF4, with or without the gdb index, and it also noticeably increases memory usage. --=20 Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=3Demail ------- You are receiving this mail because: ------- You are on the CC list for the bug.