Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752271Ab3IENRh (ORCPT ); Thu, 5 Sep 2013 09:17:37 -0400 Received: from mail-la0-f52.google.com ([209.85.215.52]:49626 "EHLO mail-la0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750712Ab3IENRf (ORCPT ); Thu, 5 Sep 2013 09:17:35 -0400 MIME-Version: 1.0 In-Reply-To: References: <1378317854-25965-1-git-send-email-jean.pihet@linaro.org> <1378317854-25965-4-git-send-email-jean.pihet@linaro.org> <20130905124508.GE9696@mudshark.cambridge.arm.com> Date: Thu, 5 Sep 2013 15:17:30 +0200 Message-ID: Subject: Re: [PATCH 3/3] perf: parse the .debug_frame section in case .eh_frame is not present From: Ard Biesheuvel To: Jean Pihet Cc: Will Deacon , "linaro-kernel@lists.linaro.org" , "patches@linaro.org" , Michael Hudson-Doyle , "linux-kernel@vger.kernel.org" , Jean Pihet , Jiri Olsa , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5165 Lines: 150 On 5 September 2013 15:05, Jean Pihet wrote: [..] > Here are the commands I have been using: > perf record -g dwarf -- > perf report --sort symbol --call-graph --stdio > Ah, I failed to add the 'dwarf' after -g, however, in that case, my perf report segfaults: #0 locate_debug_info (as=0xb6ea9144 , info=info@entry=0x83d6, addr=addr@entry=0, dlname=0x4a0000

) at dwarf/Gfind_proc_info-lsb.c:295 #1 0xb6e9a9c6 in _Uarm_dwarf_find_debug_frame (found=found@entry=0, di_debug=di_debug@entry=0xbeff95b8, info=info@entry=0x83d6, ip=ip@entry=0) at dwarf/Gfind_proc_info-lsb.c:423 #2 0x0006f0e4 in find_proc_info (as=0x2c06a0, ip=33750, pi=0xbeffa8fc, need_unwind_info=1, arg=0xbeffe530) at util/unwind.c:339 #3 0xb6e98258 in fetch_proc_info (c=c@entry=0xbeffa4d4, ip=, need_unwind_info=need_unwind_info@entry=1) at dwarf/Gparser.c:422 #4 0xb6e99640 in uncached_dwarf_find_save_locs (c=0xbeffa4d4) at dwarf/Gparser.c:824 #5 _Uarm_dwarf_find_save_locs (c=c@entry=0xbeffa4d4) at dwarf/Gparser.c:849 #6 0xb6e9a034 in _Uarm_dwarf_step (c=c@entry=0xbeffa4d4) at dwarf/Gstep.c:34 #7 0xb6e95182 in _Uarm_step (cursor=cursor@entry=0xbeffa4d4) at arm/Gstep.c:177 #8 0x0006ed50 in get_entries (ui=ui@entry=0xbeffe530, cb=cb@entry=0x47599 , arg=arg@entry=0xb6b804c8) at util/unwind.c:573 #9 0x0006f324 in unwind__get_entries (cb=cb@entry=0x47599 , arg=0xb6b804c8, machine=machine@entry=0xf0544, thread=thread@entry=0x101860, sample_uregs=sample_uregs@entry=65535, data=data@entry=0xbeffe740) at util/unwind.c:608 #10 0x00049a96 in machine__resolve_callchain (machine=machine@entry=0xf0544, evsel=evsel@entry=0xf0b98, thread=0x101860, sample=sample@entry=0xbeffe740, parent=parent@entry=0xbeffe644) at util/machine.c:1262 #11 0x0001a43e in perf_evsel__add_hist_entry (machine=0xf0544, sample=0xbeffe740, al=0xbeffe640, evsel=0xf0b98) at builtin-report.c:256 #12 process_sample_event (tool=0xbeffeb68, event=0xb6b3c600, sample=0xbeffe740, evsel=0xf0b98, machine=0xf0544) at builtin-report.c:335 #13 0x0004b3ca in perf_session_deliver_event (session=session@entry=0xf0498, event=0xb6b3c600, sample=sample@entry=0xbeffe740, tool=tool@entry=0xbeffeb68, file_offset=file_offset@entry=161280) at util/session.c:873 #14 0x0004b8d0 in flush_sample_queue (s=s@entry=0xf0498, tool=tool@entry=0xbeffeb68) at util/session.c:521 #15 0x0004c974 in __perf_session__process_events (session=session@entry=0xf0498, data_offset=, data_size=data_size@entry=437976, file_size=438264, tool=tool@entry=0xbeffeb68) at util/session.c:1269 #16 0x0004cc5c in perf_session__process_events (self=self@entry=0xf0498, tool=tool@entry=0xbeffeb68) at util/session.c:1286 #17 0x0001b4b2 in __cmd_report (rep=0xbeffeb68) at builtin-report.c:513 #18 cmd_report (argc=0, argv=0xbefff6c8, prefix=) at builtin-report.c:957 #19 0x0000d80e in run_builtin (p=p@entry=0xaa548 , argc=argc@entry=2, argv=argv@entry=0xbefff6c8) at perf.c:319 #20 0x0000d28a in handle_internal_command (argv=0xbefff6c8, argc=2) at perf.c:376 #21 run_argv (argv=0xbefff4a8, argcp=0xbefff4ac) at perf.c:420 #22 main (argc=2, argv=0xbefff6c8) at perf.c:521 -- Ard. >> >> E.g. the following stupid program (built with -O0 -g): >> >> --->8 >> >> void bar(void) >> { >> int i; >> for (i = 0; i < 1000000; ++i) >> asm volatile("nop" ::: "memory"); >> } >> >> void foo(void) >> { >> bar(); >> } >> >> >> int main(void) >> { >> foo(); >> return 0; >> } >> >> 8<--- >> >> Gives me an incomplete callchain: >> >> # Overhead Command Shared Object Symbol >> # ........ ........ ................. ............................... >> # >> 0.00% unwindme unwindme [.] bar >> | >> --- bar > I get the following with a simple stupid program with a long call chain: > 0.57% stress_bt stress_bt [.] foo_115 > | > --- foo_115 > foo_114 > foo_113 > ... > foo_92 > bar > doit > main > __libc_start_main > > Things to check: > - compile the binaries and libraries with -g (-dbg flavor of libs are > usually ok), > - use -g dwarf in perf record > > >> This is the same with or without your patch. >> >> Will > > Thanks for testing! > Jean > >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/