[PATCH] ftracetest: Fix hist unsupported result in hist selftests

From: Steven Rostedt (Red Hat)
Date: Mon May 23 2016 - 15:06:30 EST


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@xxxxxxxxxxxxxxxxxx

Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Fixes: 76929ab51f0ee ("kselftests/ftrace: Add hist trigger testcases")
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
.../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"
--
1.9.3