summaryrefslogtreecommitdiff
path: root/tools
diff options
context:
space:
mode:
authorJin Yao <yao.jin@linux.intel.com>2019-01-03 15:40:45 +0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2019-01-03 12:12:18 -0300
commit8a99255a50c0b4c2a449b96fd8d45fcc8d72c701 (patch)
tree92c075501a88953397d4625e65e1e4e7af76c7a3 /tools
parent2573be22e5b6f24a0cabc97715c808c47e29eaaf (diff)
perf stat: Fix endless wait for child process
We hit a 'perf stat' issue by using following script: #!/bin/bash sleep 1000 & exec perf stat -a -e cycles -I1000 -- sleep 5 Since "perf stat" is launched by exec, the "sleep 1000" would be the child process of "perf stat". The wait4() call will not return because it's waiting for the child process "sleep 1000" to end. So 'perf stat' doesn't return even after 5s passes. This patch lets 'perf stat' return when the specified child process ends (in this case, the specified child process is "sleep 5"). Committer testing: # cat test.sh #!/bin/bash sleep 10 & exec perf stat -a -e cycles -I1000 -- sleep 5 # Before: # time ./test.sh # time counts unit events 1.001113090 108,453,351 cycles 2.002062196 142,075,435 cycles 3.002896194 164,801,068 cycles 4.003731666 107,062,140 cycles 5.002068867 112,241,832 cycles real 0m10.066s user 0m0.016s sys 0m0.101s # After: # time ./test.sh # time counts unit events 1.001016096 91,412,027 cycles 2.002014963 124,063,708 cycles 3.002883964 125,993,929 cycles 4.003706470 120,465,734 cycles 5.002006778 163,560,355 cycles real 0m5.123s user 0m0.014s sys 0m0.105s # Signed-off-by: Jin Yao <yao.jin@linux.intel.com> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1546501245-4512-1-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/builtin-stat.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1410d66192f7..63a3afc7f32b 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -561,7 +561,8 @@ try_again:
break;
}
}
- wait4(child_pid, &status, 0, &stat_config.ru_data);
+ if (child_pid != -1)
+ wait4(child_pid, &status, 0, &stat_config.ru_data);
if (workload_exec_errno) {
const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg));