[PATCH -tip v2 0/6] perf script: add BTS analysis features

Akihiro Nagai
2011-07-17T09:29:58Z

Hi Frederic, David,

This patch series adds the functions to analyze BTS logs to perf-script and,
makes perf-script more informative version 2.
The patches add the following functions.
- Output correct IP address
- Output "(unknown)" as symbol name when perf-script can't resolve symbols.
- Output "[unknown]" as DSO name when perf-script can't resolve DSO path.
- Resolve DSOs and symbols for user-space address
- Resolve DSOs and symbols for BTS's branch_from addresses
- Show the offset of symbols with the 'offs' field specifier.
- Resolve the real path of [kernel.kallsym] using
'--show-kernel-path' option.

Usage:
First, get the BTS log with the following command.
# perf record -e branches:u -c 1 -d <command>

Second, analyze that trace data.
# perf script -f ip,addr,sym,offs,dso [--show-kernel-path]
This command's output format is:
<branch_to addr> <branch_to function+offset> <branch_to DSO> <branch_from addr> <branch_from function+offset> <branch_from DSO>

Output sample:
# perf record -e branches:u -c 1 -d ls
[snip]
# perf script -f ip,addr,sym,dso,offs --show-kernel-path

301ec016b0 (unknown) (/lib/modules/3.0.0-rc6-tip+/build/vmlinux) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
301ec016b0 _start+0x0 (/lib64/ld-2.14.so) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
301ec04b70 _dl_start+0x0 (/lib64/ld-2.14.so) 301ec016b3 _start+0x3 (/lib64/ld-2.14.so)
301ec04b70 _dl_start+0x0 (/lib64/ld-2.14.so) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
301ec04b96 _dl_start+0x26 (/lib64/ld-2.14.so) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
301ec04b9d _dl_start+0x2d (/lib64/ld-2.14.so) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
301ec04c0d _dl_start+0x9d (/lib64/ld-2.14.so) 301ec04beb _dl_start+0x7b (/lib64/ld-2.14.so)
[snip]
401fd0 main+0x0 (/root/bin/ls) 301f021399 __libc_start_main+0xe9 (/lib64/libc-2.14.so)
409ad0 set_program_name+0x0 (/root/bin/ls) 401ff3 main+0x23 (/root/bin/ls)
409ad0 set_program_name+0x0 (/root/bin/ls) ffffffff81467612 irq_return+0x0 (/lib/modules/3.0.0-rc6-tip+/build/vmlinux)
401ca8 strrchr@plt+0x0 (/root/bin/ls) 409ade set_program_name+0xe (/root/bin/ls)
401cae strrchr@plt+0x6 (/root/bin/ls) 401ca8 strrchr@plt+0x0 (/root/bin/ls)
401a38 _init+0x18 (/root/bin/ls) 401cb3 strrchr@plt+0xb (/root/bin/ls)
301ec13840 _dl_runtime_resolve+0x0 (/lib64/ld-2.14.so) 401a3e _init+0x1e (/root/bin/ls)
301ec0d6a0 _dl_fixup+0x0 (/lib64/ld-2.14.so) 301ec13870 _dl_runtime_resolve+0x30 (/lib64/ld-2.14.so)
[snip]

It shows the tracee application's execution path.

TODO:
- add source code path field, line number field ...etc.
- add record/report script to use easily and, show human-friendly output.
- filtering kernel functions using scripts

Changes in v2:
- add a bug fix patch that prints correct IP address
- output the magic word "(unknown)" as symbol name when perf-script can't
resolve symbols.
- output "[unknown]" as DSO name when perf-script can't resolve DSO path.
- change the way to output offset of symbols from '--show-symbol-offset' to
'offs' field.
- clean up codes.

Thanks,

---

Akihiro Nagai (6):
perf script: add option resolving vmlinux path
perf script: add the offset field specifier
perf script: print DSOs and symbols for BTS branch_from addr
perf script: resolve DSOs and symbols for user-space
perf script: add magic word to indicate the failure of resolving symbols
[BUGFIX] perf script: print correct IP address

tools/perf/Documentation/perf-script.txt | 5 +++
tools/perf/builtin-script.c | 46 +++++++++++++++++++++---------
tools/perf/util/event.c | 5 +++
tools/perf/util/map.c | 15 ++++++++++
tools/perf/util/map.h | 1 +
tools/perf/util/session.c | 42 ++++++++++-----------------
tools/perf/util/session.h | 3 +-
tools/perf/util/symbol.c | 21 ++++++++++++++
tools/perf/util/symbol.h | 4 +++
9 files changed, 100 insertions(+), 42 deletions(-)

--
Akihiro Nagai (akihiro.nagai.hw@hitachi.com)