diff options
| author | Kan Liang <kan.liang@intel.com> | 2015-01-05 19:23:04 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-02-18 17:16:17 +0100 |
| commit | aad2b21c151273fa7abc419dac51a980eff1dd17 (patch) | |
| tree | 6408263bd2daf71567178e4fe07d094de934414c /tools/perf/builtin-report.c | |
| parent | perf/x86/intel: Expose LBR callstack to user space tooling (diff) | |
| download | linux-aad2b21c151273fa7abc419dac51a980eff1dd17.tar.xz linux-aad2b21c151273fa7abc419dac51a980eff1dd17.zip | |
perf tools: Enable LBR call stack support
Currently, there are two call chain recording options, fp and dwarf.
Haswell has a new feature that utilizes the existing LBR facility to
record call chains. Kernel side LBR support code provides this as a
third option to record call chains. This patch enables the lbr call
stack support on the tooling side.
LBR call stack has some limitations:
- It reuses current LBR facility, so LBR call stack and branch record
can not be enabled at the same time.
- It is only available for user-space callchains.
However, it also offers some advantages:
- LBR call stack can work on user apps which don't have frame-pointers
or dwarf debug info compiled. It is a good alternative when nothing
else works.
Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Jacob Shin <jacob.w.shin@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masanari Iida <standby24x7@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodrigo Campos <rodrigo@sdfg.com.ar>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1420482185-29830-2-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/perf/builtin-report.c')
| -rw-r--r-- | tools/perf/builtin-report.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index 2f91094e228b..0ba5f07906fb 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -249,6 +249,8 @@ static int report__setup_sample_type(struct report *rep) if ((sample_type & PERF_SAMPLE_REGS_USER) && (sample_type & PERF_SAMPLE_STACK_USER)) callchain_param.record_mode = CALLCHAIN_DWARF; + else if (sample_type & PERF_SAMPLE_BRANCH_STACK) + callchain_param.record_mode = CALLCHAIN_LBR; else callchain_param.record_mode = CALLCHAIN_FP; } |