|From:||Jiri Olsa <email@example.com>|
|To:||firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com|
|Subject:||[RFCv3 00/17] perf: Add backtrace post dwarf unwind|
|Date:||Wed, 2 May 2012 13:37:01 +0200|
|Cc:||firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com|
hi, sending another RFC version. This mainly includes more general version of perf regs and stack interface. Details are below and in patches' comments.. ;) thanks for comments, jirka 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: 01/17 perf: Unified API to record selective sets of arch registers 02/17 perf: Add ability to attach registers dump to sample 03/17 perf: Factor __output_copy to be usable with specific copy function 04/17 perf: Add ability to attach user stack dump to sample 05/17 perf: Add attribute to filter out user callchains 06/17 perf, tool: Fix format string for x86-32 compilation 07/17 perf, tool: Factor DSO symtab types to generic binary types 08/17 perf, tool: Add interface to read DSO image data 09/17 perf, tool: Add '.note' check into search for NOTE section 10/17 perf, tool: Back [vdso] DSO with real data 11/17 perf, tool: Add interface to arch registers sets 12/17 perf, tool: Add libunwind dependency for dwarf cfi unwinding 13/17 perf, tool: Support user regs and stack in sample parsing 14/17 perf, tool: Support for dwarf cfi unwinding on post processing 15/17 perf, tool: Support for dwarf mode callchain on perf record 16/17 perf, tool: Add dso data caching 17/17 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 | 10 + arch/x86/include/asm/perf_regs_32.h | 84 +++ arch/x86/include/asm/perf_regs_64.h | 99 ++++ include/linux/perf_event.h | 49 ++- include/linux/perf_regs.h | 28 + kernel/events/callchain.c | 4 +- kernel/events/core.c | 204 +++++++- kernel/events/internal.h | 65 ++- kernel/events/ring_buffer.c | 4 +- tools/perf/Makefile | 45 ++- tools/perf/arch/x86/Makefile | 3 + tools/perf/arch/x86/include/perf_regs.h | 108 ++++ tools/perf/arch/x86/util/unwind.c | 111 ++++ tools/perf/builtin-record.c | 86 +++- tools/perf/builtin-report.c | 26 +- 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.c | 154 ++++++ tools/perf/util/event.h | 16 +- tools/perf/util/evlist.c | 24 + tools/perf/util/evlist.h | 3 + tools/perf/util/evsel.c | 43 ++- tools/perf/util/include/linux/compiler.h | 1 + tools/perf/util/map.c | 23 +- tools/perf/util/map.h | 7 +- tools/perf/util/perf_regs.h | 19 + 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 | 134 +++++- tools/perf/util/session.h | 15 +- 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 + 46 files changed, 2488 insertions(+), 193 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to firstname.lastname@example.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Copyright © 2012, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds