[PATCH 01/15] perf callchain: Recording 'dwarf' callchains do not need DWARF unwinding support

From: Arnaldo Carvalho de Melo
Date: Tue May 10 2016 - 11:16:39 EST


From: He Kuang <hekuang@xxxxxxxxxx>

There is no need to check for DWARF unwinding support when using the
'dwarf' callchain record method, as this will only ask the kernel to
collect stack dumps for later DWARF CFI processing, which can be done in
another machine, where the support for DWARF unwinding need to be
present.

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ekaterina Tumanova <tumanova@xxxxxxxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1462525154-125656-2-git-send-email-hekuang@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/util.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 619ba2061b62..01c9433de7ef 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -507,7 +507,6 @@ int parse_callchain_record(const char *arg, struct callchain_param *param)
"needed for --call-graph fp\n");
break;

-#ifdef HAVE_DWARF_UNWIND_SUPPORT
/* Dwarf style */
} else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
const unsigned long default_stack_dump_size = 8192;
@@ -523,7 +522,6 @@ int parse_callchain_record(const char *arg, struct callchain_param *param)
ret = get_stack_size(tok, &size);
param->dump_size = size;
}
-#endif /* HAVE_DWARF_UNWIND_SUPPORT */
} else if (!strncmp(name, "lbr", sizeof("lbr"))) {
if (!strtok_r(NULL, ",", &saveptr)) {
param->record_mode = CALLCHAIN_LBR;
--
2.5.5