[tip:perf/core] perf callchain: Recording 'dwarf' callchains do not need DWARF unwinding support

From: tip-bot for He Kuang
Date: Tue May 10 2016 - 16:31:28 EST


Commit-ID: 841e3558b2de6d8c53dae4f01c7a81cd53e42e5c
Gitweb: http://git.kernel.org/tip/841e3558b2de6d8c53dae4f01c7a81cd53e42e5c
Author: He Kuang <hekuang@xxxxxxxxxx>
AuthorDate: Fri, 6 May 2016 08:59:07 +0000
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 9 May 2016 13:29:36 -0300

perf callchain: Recording 'dwarf' callchains do not need DWARF unwinding support

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 619ba20..01c9433 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;