ftracetest: Do not use usleep directly

The usleep is only provided on distros from Redhat so running ftracetest
on other distro resulted in failures due to the missing usleep.

The reason of using [u]sleep in the test was to generate (scheduler)
events.  It can be done various ways like this:

yield() {  ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1; }

For more information to the history of this patch, please refer to:

Link: http://lkml.kernel.org/r/1427329943-16896-1-git-send-email-namhyung@kernel.org

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Suggested-by: Pádraig Brady <P@draigBrady.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
diff --git a/tools/testing/selftests/ftrace/test.d/event/event-enable.tc b/tools/testing/selftests/ftrace/test.d/event/event-enable.tc
index dbddb78..87eb9d6 100644
--- a/tools/testing/selftests/ftrace/test.d/event/event-enable.tc
+++ b/tools/testing/selftests/ftrace/test.d/event/event-enable.tc
@@ -12,6 +12,10 @@
     exit $FAIL
 }
 
+yield() {
+    ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1
+}
+
 if [ ! -f set_event -o ! -d events/sched ]; then
     echo "event tracing is not supported"
     exit_unsupported
@@ -21,7 +25,8 @@
 do_reset
 
 echo 'sched:sched_switch' > set_event
-usleep 1
+
+yield
 
 count=`cat trace | grep sched_switch | wc -l`
 if [ $count -eq 0 ]; then
@@ -31,7 +36,8 @@
 do_reset
 
 echo 1 > events/sched/sched_switch/enable
-usleep 1
+
+yield
 
 count=`cat trace | grep sched_switch | wc -l`
 if [ $count -eq 0 ]; then
@@ -41,7 +47,8 @@
 do_reset
 
 echo 0 > events/sched/sched_switch/enable
-usleep 1
+
+yield
 
 count=`cat trace | grep sched_switch | wc -l`
 if [ $count -ne 0 ]; then
diff --git a/tools/testing/selftests/ftrace/test.d/event/subsystem-enable.tc b/tools/testing/selftests/ftrace/test.d/event/subsystem-enable.tc
index ef9b95d..ced27ef 100644
--- a/tools/testing/selftests/ftrace/test.d/event/subsystem-enable.tc
+++ b/tools/testing/selftests/ftrace/test.d/event/subsystem-enable.tc
@@ -12,6 +12,10 @@
     exit $FAIL
 }
 
+yield() {
+    ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1
+}
+
 if [ ! -f set_event -o ! -d events/sched ]; then
     echo "event tracing is not supported"
     exit_unsupported
@@ -21,7 +25,8 @@
 do_reset
 
 echo 'sched:*' > set_event
-usleep 1
+
+yield
 
 count=`cat trace | grep -v ^# | awk '{ print $5 }' | sort -u | wc -l`
 if [ $count -lt 3 ]; then
@@ -31,7 +36,8 @@
 do_reset
 
 echo 1 > events/sched/enable
-usleep 1
+
+yield
 
 count=`cat trace | grep -v ^# | awk '{ print $5 }' | sort -u | wc -l`
 if [ $count -lt 3 ]; then
@@ -41,7 +47,8 @@
 do_reset
 
 echo 0 > events/sched/enable
-usleep 1
+
+yield
 
 count=`cat trace | grep -v ^# | awk '{ print $5 }' | sort -u | wc -l`
 if [ $count -ne 0 ]; then
diff --git a/tools/testing/selftests/ftrace/test.d/event/toplevel-enable.tc b/tools/testing/selftests/ftrace/test.d/event/toplevel-enable.tc
index af8cf01..0bb5df3 100644
--- a/tools/testing/selftests/ftrace/test.d/event/toplevel-enable.tc
+++ b/tools/testing/selftests/ftrace/test.d/event/toplevel-enable.tc
@@ -12,6 +12,10 @@
     exit $FAIL
 }
 
+yield() {
+    ping localhost -c 1 || sleep .001 || usleep 1 || sleep 1
+}
+
 if [ ! -f available_events -o ! -f set_event -o ! -d events ]; then
     echo "event tracing is not supported"
     exit_unsupported
@@ -21,6 +25,9 @@
 do_reset
 
 echo '*:*' > set_event
+
+yield
+
 count=`cat trace | grep -v ^# | wc -l`
 if [ $count -eq 0 ]; then
     fail "none of events are recorded"
@@ -29,6 +36,9 @@
 do_reset
 
 echo 1 > events/enable
+
+yield
+
 count=`cat trace | grep -v ^# | wc -l`
 if [ $count -eq 0 ]; then
     fail "none of events are recorded"
@@ -37,6 +47,9 @@
 do_reset
 
 echo 0 > events/enable
+
+yield
+
 count=`cat trace | grep -v ^# | wc -l`
 if [ $count -ne 0 ]; then
     fail "any of events should not be recorded"