From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757227Ab2CEW1B (ORCPT ); Mon, 5 Mar 2012 17:27:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63365 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756689Ab2CEW1A (ORCPT ); Mon, 5 Mar 2012 17:27:00 -0500 Date: Mon, 5 Mar 2012 19:26:14 -0300 From: Arnaldo Carvalho de Melo To: Arun Sharma Cc: Peter Zijlstra , Ingo Molnar , Stephane Eranian , linux-kernel@vger.kernel.org, dsahern@gmail.com, ravitillo@lbl.gov, khandual@linux.vnet.ibm.com, robert.richter@amd.com, ming.m.lin@intel.com, vweaver1@eecs.utk.edu, andi@firstfloor.org Subject: Re: [PATCH] perf report: auto-detect branch stack sampling mode Message-ID: <20120305222614.GB5656@infradead.org> References: <20120224094048.GA7952@quad> <20120305154753.GA14604@elte.hu> <20120305155011.GA32413@elte.hu> <20120305155642.GB32413@elte.hu> <1330965033.11248.240.camel@twins> <20120305203518.GA5656@infradead.org> <4F55337B.4080807@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F55337B.4080807@fb.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Mar 05, 2012 at 01:43:23PM -0800, Arun Sharma escreveu: > On 3/5/12 12:35 PM, Arnaldo Carvalho de Melo wrote: > >Em Mon, Mar 05, 2012 at 05:30:33PM +0100, Peter Zijlstra escreveu: > >>On Mon, 2012-03-05 at 16:56 +0100, Ingo Molnar wrote: > >Do you have any specific complaints about it? > > I think --tui code paths have some bugs that cause it to SIGSEGV, > while the --stdio paths don't. I think much of it has to do with how We'll have the same problem with --gtk, i.e. as much as we librarise the backend code, there will be bugs in the frontends, but then we'll fix as in this case. What I was more concerned was what usability problems Peter and Stephane had with the TUI, i.e. any missing feature they like on --stdio, or any annoyance wrt color schemes, key bindings, etc. I made an effort to try and have the look and feel of the TUI to resemble as much as possible the one in --stdio, while allowing usability improvements not possible in the --stdio case, like: . Folding/unfolding callchains . Zooming by DSO, etc . Going to annotate and back really quickly . Initial support for navigation in the annotate window (just callq for now, but jumps, etc are on the plans) . Toggling source code on/off on the annotation window > often that particular combination of command line options is used. > > Here's an example: > > # perf record -ag -- sleep 3 > # perf report -G -s pid --tui # SIGSEGV Ok, now this is a good report, I managed to reproduce and will work on a fix, thanks, - Arnaldo > # perf report -G -s pid --stdio # works fine > > Details attached. > > -Arun > > > > > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 139975795275488 (LWP 13155)] > symbol__inc_addr_samples (sym=0x91eb90, map=, evidx=0, addr=120416) at util/annotate.c:73 > 73 util/annotate.c: No such file or directory. > in util/annotate.c > (gdb) bt > #0 symbol__inc_addr_samples (sym=0x91eb90, map=, evidx=0, addr=120416) at util/annotate.c:73 > #1 0x0000000000410b5d in process_sample_event (tool=, event=0x7f4ea28e26b0, sample=0x7fffcc1ca8f0, evsel=0x823ea0, machine=0x822290) at builtin-report.c:127 > #2 0x00000000004433ca in flush_sample_queue (s=0x822230, tool=0x7fffcc1cc340) at util/session.c:528 > #3 0x0000000000444d16 in __perf_session__process_events (session=0x822230, data_offset=, data_size=, file_size=, tool=0x7fffcc1cc340) > at util/session.c:1175 > #4 0x0000000000445217 in perf_session__process_events (self=0x822230, tool=0x7fffcc1cc340) at util/session.c:1191 > #5 0x000000000041015b in cmd_report (argc=0, argv=0x7fffcc1cc830, prefix=) at builtin-report.c:311 > #6 0x00000000004051b9 in handle_internal_command (argc=4, argv=0x7fffcc1cc830) at perf.c:273 > #7 0x0000000000405623 in main (argc=4, argv=0x479218) at perf.c:388 > > (gdb) p /x sym->start > $5 = 0xffffffff8100fb74 > (gdb) p /x addr > $6 = 0x1d660 > (gdb) p offset > $7 = 2130762476 > > 54 int symbol__inc_addr_samples(struct symbol *sym, struct map *map, > 55 int evidx, u64 addr) > 56 { > 57 unsigned offset; > 58 struct annotation *notes; > 59 struct sym_hist *h; > 60 > 61 notes = symbol__annotation(sym); > 62 if (notes->src == NULL) > 63 return -ENOMEM; > 64 > 65 pr_debug3("%s: addr=%#" PRIx64 "\n", __func__, map->unmap_ip(map, addr)); > 66 > 67 if (addr >= sym->end) > 68 return 0; > 69 > 70 offset = addr - sym->start; > 71 h = annotation__histogram(notes, evidx); > 72 h->sum++; > 73 h->addr[offset]++; <-- potential bad memory reference