Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753436Ab2FKNUs (ORCPT ); Mon, 11 Jun 2012 09:20:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750825Ab2FKNUq (ORCPT ); Mon, 11 Jun 2012 09:20:46 -0400 From: Jiri Olsa To: acme@redhat.com, a.p.zijlstra@chello.nl, mingo@elte.hu, paulus@samba.org, cjashfor@linux.vnet.ibm.com, fweisbec@gmail.com Cc: eranian@google.com, gorcunov@openvz.org, tzanussi@gmail.com, mhiramat@redhat.com, robert.richter@amd.com, fche@redhat.com, linux-kernel@vger.kernel.org, masami.hiramatsu.pt@hitachi.com, drepper@gmail.com, asharma@fb.com, benjamin.redelings@nescent.org Subject: [RFCv5 00/19] perf: Add backtrace post dwarf unwind Date: Mon, 11 Jun 2012 15:19:55 +0200 Message-Id: <1339420814-7379-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8213 Lines: 179 hi, besides fixing several issues, going back to the original design because the last one was considered too generic.. now we have: sample_regs_user - != 0 triggers the user level regs dump sample_stack_user - != 0 triggers the user stack dump We can allway extend this in future with new mask and flags for IRQ/PEBS regs. patches available also as tarball in here: http://people.redhat.com/~jolsa/perf_post_unwind_v5.tar.bz2 v5 changes: patch 1/19 - having just one enum set of the perf registers patch 2/19 - using for_each_set_bit for scanning the mask - single regs enum for both 32 and 64 bits versions - using regs mask != 0 trigger to trigger the regs dump patch 5/19 - adding perf_output_skip so we can skip undumped part of the stack in RB patch 6/19 - using stack size != 0 trigger to trigger the stack dump - do not zero the memory for non retrieved part of the stack dump patch 7/19 - adding exclude_callchain_kernel attribute patch 8/19 - this could be taken without the rest of the series v4 changes: - no real change from v3, just rebase - v3 patch 06/17 got already merged v3 changes: patch 01/17 - added HAVE_PERF_REGS config option patch 02/17, 04/17 - regs and stack perf interface is more general now patch 06/17 - unrelated online fix for i386 compilation patch 16/17 - few namespace fixies --- Adding the post unwinding user stack backtrace using dwarf unwind via libunwind. The original work was done by Frederic. I mostly took his patches and make them compile in current kernel code plus I added some stuff here and there. The main idea is to store user registers and portion of user stack when the sample data during the record phase. Then during the report, when the data is presented, perform the actual dwarf dwarf unwind. attached patches: 01/19 perf: Unified API to record selective sets of arch registers 02/19 perf: Add ability to attach user level registers dump to sample 03/19 perf, x86: Add copy_from_user_nmi_nochk for best effort copy 04/19 perf: Factor __output_copy to be usable with specific copy function 05/19 perf: Add perf_output_skip function to skip bytes in sample 06/19 perf: Add ability to attach user stack dump to sample 07/19 perf: Add attribute to filter out callchains 08/19 perf, tool: Remove unsused evsel parameter from machine__resolve_callchain 09/19 perf, tool: Factor DSO symtab types to generic binary types 10/19 perf, tool: Add interface to read DSO image data 11/19 perf, tool: Add '.note' check into search for NOTE section 12/19 perf, tool: Back [vdso] DSO with real data 13/19 perf, tool: Add interface to arch registers sets 14/19 perf, tool: Add libunwind dependency for dwarf cfi unwinding 15/19 perf, tool: Support user regs and stack in sample parsing 16/19 perf, tool: Support for dwarf cfi unwinding on post processing 17/19 perf, tool: Support for dwarf mode callchain on perf record 18/19 perf, tool: Add dso data caching 19/19 perf, tool: Add dso data caching tests I tested on Fedora. There was not much gain on i386, because the binaries are compiled with frame pointers. Thought the dwarf backtrace is more accurade and unwraps calls in more details (functions that do not set the frame pointers). I could see some improvement on x86_64, where I got full backtrace where current code could got just the first address out of the instruction pointer. Example on x86_64: [dwarf] perf record -g -e syscalls:sys_enter_write date 100.00% date libc-2.14.90.so [.] __GI___libc_write | --- __GI___libc_write _IO_file_write@@GLIBC_2.2.5 new_do_write _IO_do_write@@GLIBC_2.2.5 _IO_file_overflow@@GLIBC_2.2.5 0x4022cd 0x401ee6 __libc_start_main 0x4020b9 [frame pointer] perf record -g fp -e syscalls:sys_enter_write date 100.00% date libc-2.14.90.so [.] __GI___libc_write | --- __GI___libc_write Also I tested on coreutils binaries mainly, but I could see getting wider backtraces with dwarf unwind for more complex application like firefox. The unwind should go throught [vdso] object. I haven't studied the [vsyscall] yet, so not sure there. Attached patches should work on both x86 and x86_64. I did some initial testing so far. The unwind backtrace can be interrupted by following reasons: - bug in unwind information of processed shared library - bug in unwind processing code (most likely ;) ) - insufficient dump stack size - wrong register value - x86_64 does not store whole set of registers when in exception, but so far it looks like RIP and RSP should be enough thanks for comments, jirka --- arch/Kconfig | 6 + arch/x86/Kconfig | 1 + arch/x86/include/asm/perf_event.h | 2 + arch/x86/include/asm/perf_regs.h | 34 ++ arch/x86/include/asm/uaccess.h | 2 + arch/x86/kernel/Makefile | 2 + arch/x86/kernel/perf_regs.c | 91 ++++ arch/x86/lib/usercopy.c | 15 +- include/linux/perf_event.h | 24 +- include/linux/perf_regs.h | 19 + kernel/events/callchain.c | 25 +- kernel/events/core.c | 132 +++++- kernel/events/internal.h | 69 ++- kernel/events/ring_buffer.c | 10 +- tools/perf/Makefile | 45 ++- tools/perf/arch/x86/Makefile | 3 + tools/perf/arch/x86/include/perf_regs.h | 80 +++ tools/perf/arch/x86/util/unwind.c | 111 ++++ tools/perf/builtin-record.c | 86 +++- tools/perf/builtin-report.c | 24 +- tools/perf/builtin-script.c | 56 ++- tools/perf/builtin-test.c | 7 +- tools/perf/builtin-top.c | 7 +- tools/perf/config/feature-tests.mak | 25 + tools/perf/perf.h | 9 +- tools/perf/util/annotate.c | 2 +- tools/perf/util/dso-test-data.c | 154 ++++++ tools/perf/util/event.h | 15 +- tools/perf/util/evlist.c | 16 + tools/perf/util/evlist.h | 2 + tools/perf/util/evsel.c | 35 ++- tools/perf/util/include/linux/compiler.h | 1 + tools/perf/util/map.c | 23 +- tools/perf/util/map.h | 9 +- tools/perf/util/perf_regs.h | 14 + tools/perf/util/python.c | 3 +- .../perf/util/scripting-engines/trace-event-perl.c | 3 +- .../util/scripting-engines/trace-event-python.c | 3 +- tools/perf/util/session.c | 110 ++++- tools/perf/util/session.h | 17 +- tools/perf/util/symbol.c | 435 +++++++++++++--- tools/perf/util/symbol.h | 52 ++- tools/perf/util/trace-event-scripting.c | 3 +- tools/perf/util/trace-event.h | 5 +- tools/perf/util/unwind.c | 565 ++++++++++++++++++++ tools/perf/util/unwind.h | 34 ++ tools/perf/util/vdso.c | 90 +++ tools/perf/util/vdso.h | 8 + 48 files changed, 2278 insertions(+), 206 deletions(-) -- 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/