From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18740 invoked by alias); 22 Sep 2009 10:10:15 -0000 Received: (qmail 18634 invoked by uid 48); 22 Sep 2009 10:09:59 -0000 Date: Tue, 22 Sep 2009 10:10:00 -0000 Message-ID: <20090922100959.18633.qmail@sourceware.org> From: "mjw at redhat dot com" To: systemtap@sources.redhat.com In-Reply-To: <20090920165213.10671.mjw@redhat.com> References: <20090920165213.10671.mjw@redhat.com> Reply-To: sourceware-bugzilla@sourceware.org Subject: [Bug testsuite/10671] semok/twenty.stp takes 15 minutes on slow/low-memory machine X-Bugzilla-Reason: AssignedTo Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2009-q3/txt/msg00825.txt.bz2 ------- Additional Comments From mjw at redhat dot com 2009-09-22 10:09 ------- (In reply to comment #3) > Then, random SIGINT/backtraces appear to > implicate translate.cxx:4740, the call to dwfl_module_address_section(). Yes, this is another case where libdwfl decides to start relocating things just because we want to get at the section header. In this case we only need the shdr->sh_size, not the actual data. But there seems to be no way to get that information, through libdwfl, without triggering a full relocation of the elf file. This is actually part of a long standing discussion between Roland and myself: http://sourceware.org/ml/systemtap/2008-q4/msg00597.html The basic idea is that we try to build up a search table for addresses that can be mapped to modules, and for that we want to know the size of the module. Roland feels this should be done differently/isn't needed. But I don't know how else we can get this working correctly without knowing the module sizes. Note that it could very well be that the confusion is amplified by the fact that previous versions of elfutils had some bugs in dwfl_module_relocate_address(). The thread referenced above is mainly about working around that bug. IMHO, like in the other case, it would be nice if libdwfl would just let us get at the "raw" elf section header/data without feeling the need to relocate it all unless we explicitly request it does so. -- What |Removed |Added ---------------------------------------------------------------------------- Summary|semok/twenty.stp takes 15 |semok/twenty.stp takes 15 |minutes on slow/low-memorry |minutes on slow/low-memory |machine |machine http://sourceware.org/bugzilla/show_bug.cgi?id=10671 ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee.