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authorKan Liang <kan.liang@intel.com>2015-01-05 13:23:04 -0500
committerIngo Molnar <mingo@kernel.org>2015-02-18 17:16:17 +0100
commitaad2b21c151273fa7abc419dac51a980eff1dd17 (patch)
tree6408263bd2daf71567178e4fe07d094de934414c /tools/perf/builtin-record.c
parent2c44b1936bb3b135a3fac8b3493394d42e51cf70 (diff)
downloadlinux-aad2b21c151273fa7abc419dac51a980eff1dd17.tar.gz
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-record.c')
-rw-r--r--tools/perf/builtin-record.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 404ab3434052..d0d02a811ecd 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -658,7 +658,7 @@ error:
static void callchain_debug(void)
{
- static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF" };
+ static const char *str[CALLCHAIN_MAX] = { "NONE", "FP", "DWARF", "LBR" };
pr_debug("callchain: type %s\n", str[callchain_param.record_mode]);
@@ -751,9 +751,9 @@ static struct record record = {
#define CALLCHAIN_HELP "setup and enables call-graph (stack chain/backtrace) recording: "
#ifdef HAVE_DWARF_UNWIND_SUPPORT
-const char record_callchain_help[] = CALLCHAIN_HELP "fp dwarf";
+const char record_callchain_help[] = CALLCHAIN_HELP "fp dwarf lbr";
#else
-const char record_callchain_help[] = CALLCHAIN_HELP "fp";
+const char record_callchain_help[] = CALLCHAIN_HELP "fp lbr";
#endif
/*