From: "Steven Rostedt (Red Hat)" When histograms are not configured in the kernel, the ftracetest histogram selftests should return "unsupported" and not "Failed". To detect this, the test scripts have: FEATURE=`grep hist events/sched/sched_process_fork/trigger` if [ -z "$FEATURE" ]; then echo "hist trigger is not supported" exit_unsupported fi The problem is that '-e' is in effect and any error will cause the program to terminate. The grep for 'hist' fails, because it is not compiled it (thus unsupported), but because grep has an error code for failing to find the string, it causes the program to terminate, and is marked as a failed test. Namhyung Kim recommended to test for the "hist" file located in events/sched/sched_process_fork/hist instead, as it is more inline with the other checks. As the hist file is only created if the histogram feature is enabled, that is a valid check. Link: http://lkml.kernel.org/r/20160523151538.4ea9ce0c@gandalf.local.home Suggested-by: Namhyung Kim Acked-by: Namhyung Kim Acked-by: Masami Hiramatsu Fixes: 76929ab51f0ee ("kselftests/ftrace: Add hist trigger testcases") Signed-off-by: Steven Rostedt --- .../testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc | 9 ++++----- tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc | 9 ++++----- .../testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc | 9 ++++----- 3 files changed, 12 insertions(+), 15 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc index c2b61c4fda11..0bf5085281f3 100644 --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc @@ -23,15 +23,14 @@ if [ ! -f events/sched/sched_process_fork/trigger ]; then exit_unsupported fi -reset_tracer -do_reset - -FEATURE=`grep hist events/sched/sched_process_fork/trigger` -if [ -z "$FEATURE" ]; then +if [ ! -f events/sched/sched_process_fork/hist ]; then echo "hist trigger is not supported" exit_unsupported fi +reset_tracer +do_reset + echo "Test histogram with execname modifier" echo 'hist:keys=common_pid.execname' > events/sched/sched_process_fork/trigger diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc index b2902d42a537..a00184cd9c95 100644 --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc @@ -23,15 +23,14 @@ if [ ! -f events/sched/sched_process_fork/trigger ]; then exit_unsupported fi -reset_tracer -do_reset - -FEATURE=`grep hist events/sched/sched_process_fork/trigger` -if [ -z "$FEATURE" ]; then +if [ ! -f events/sched/sched_process_fork/hist ]; then echo "hist trigger is not supported" exit_unsupported fi +reset_tracer +do_reset + echo "Test histogram basic tigger" echo 'hist:keys=parent_pid:vals=child_pid' > events/sched/sched_process_fork/trigger diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc index 03c4a46561fc..3478b00ead57 100644 --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc @@ -23,15 +23,14 @@ if [ ! -f events/sched/sched_process_fork/trigger ]; then exit_unsupported fi -reset_tracer -do_reset - -FEATURE=`grep hist events/sched/sched_process_fork/trigger` -if [ -z "$FEATURE" ]; then +if [ ! -f events/sched/sched_process_fork/hist ]; then echo "hist trigger is not supported" exit_unsupported fi +reset_tracer +do_reset + reset_trigger echo "Test histogram multiple tiggers" -- 2.8.0.rc3