[PATCH] perf report: Fix branch stack mode cannot be set

From: He Kuang
Date: Sat Feb 14 2015 - 21:38:17 EST


When perf.data file be abtained by using 'perf record -b', perf report
should use branch stack mode to generate output. But this function is
broken by improper comparison between boolean and constant -1.

before this patch:
$perf report -b -i perf.data
Samples: 16 of event 'cycles', Event count (approx.): 3171896
Overhead Command Shared Object Symbol
13.59% ls [kernel.kallsyms] [k] prio_tree_remove
13.16% ls [kernel.kallsyms] [k] change_pte_range
12.09% ls [kernel.kallsyms] [k] page_fault
12.02% ls [kernel.kallsyms] [k] zap_pte_range
...

after this patch:
$perf report -b -i perf.data
Samples: 256 of event 'cycles', Event count (approx.): 256
Overhead Command Source Shared Object Source Symbol Target Shared Object Target Symbol
9.38% ls [unknown] [k] 0000000000000000 [unknown] [k] 0000000000000000
6.25% ls libc-2.19.so [.] _dl_addr libc-2.19.so [.] _dl_addr
6.25% ls [kernel.kallsyms] [k] zap_pte_range [kernel.kallsyms] [k] zap_pte_range
6.25% ls [kernel.kallsyms] [k] change_pte_range [kernel.kallsyms] [k] change_pte_range
0.39% ls [kernel.kallsyms] [k] prio_tree_remove [kernel.kallsyms] [k] prio_tree_remove
...

Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
---
tools/perf/builtin-report.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 2f91094..ecc453b 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -766,7 +766,7 @@ repeat:
* 0/1 means the user chose a mode.
*/
if (((branch_mode == -1 && has_br_stack) || branch_mode == 1) &&
- branch_call_mode == -1) {
+ !branch_call_mode) {
sort__mode = SORT_MODE__BRANCH;
symbol_conf.cumulate_callchain = false;
}
--
2.2.0.33.gc18b867

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