ftracetest: Fix hist unsupported result in hist selftests

0ded5174 · Steven Rostedt (Red Hat) <[email protected]> · 2016-05-23 15:06:30 -04:00

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/[email protected]

Suggested-by: Namhyung Kim <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Fixes: 76929ab51f0ee ("kselftests/ftrace: Add hist trigger testcases")
Signed-off-by: Steven Rostedt <[email protected]>

Commit

0ded5174e976e2b2a354fe38abf1ebf4492c6dc3

Parents

70c8217a

Changes

3 files changed · +12 −15