perf test: Ensure lock contention using pipe mode

The 'kernel lock contention analysis test' requires reliable triggering
of lock contention. On some systems, previous benchmark calls failed to
generate sufficient contention due to low system activity or resource
limits.

This patch adds the -p (pipe) option to all calls of perf bench sched
messaging, ensuring consistent lock contention without relying on
socket-based communication.

Suggested-by: Thomas Richter <[email protected]>
Signed-off-by: Jan Polensky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

Author: Jan Polensky

tools/perf/tests/shell/lock_contention.sh

@@ -44,7 +44,7 @@ check() {
 test_record()
 {
 	echo "Testing perf lock record and perf lock contention"
-	perf lock record -o ${perfdata} -- perf bench sched messaging > /dev/null 2>&1
+	perf lock record -o ${perfdata} -- perf bench sched messaging -p > /dev/null 2>&1
 	# the output goes to the stderr and we expect only 1 output (-E 1)
 	perf lock contention -i ${perfdata} -E 1 -q 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
@@ -64,7 +64,7 @@ test_bpf()
 	fi
 
 	# the perf lock contention output goes to the stderr
-	perf lock con -a -b -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result count is not 1:" "$(cat "${result}" | wc -l)"
 		err=1
@@ -75,7 +75,7 @@ test_bpf()
 test_record_concurrent()
 {
 	echo "Testing perf lock record and perf lock contention at the same time"
-	perf lock record -o- -- perf bench sched messaging 2> /dev/null | \
+	perf lock record -o- -- perf bench sched messaging -p 2> /dev/null | \
 	perf lock contention -i- -E 1 -q 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] Recorded result count is not 1:" "$(cat "${result}" | wc -l)"
@@ -99,7 +99,7 @@ test_aggr_task()
 	fi
 
 	# the perf lock contention output goes to the stderr
-	perf lock con -a -b -t -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -t -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result count is not 1:" "$(cat "${result}" | wc -l)"
 		err=1
@@ -122,7 +122,7 @@ test_aggr_addr()
 	fi
 
 	# the perf lock contention output goes to the stderr
-	perf lock con -a -b -l -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -l -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result count is not 1:" "$(cat "${result}" | wc -l)"
 		err=1
@@ -140,7 +140,7 @@ test_aggr_cgroup()
 	fi
 
 	# the perf lock contention output goes to the stderr
-	perf lock con -a -b -g -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -g -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result count is not 1:" "$(cat "${result}" | wc -l)"
 		err=1
@@ -162,7 +162,7 @@ test_type_filter()
 		return
 	fi
 
-	perf lock con -a -b -Y spinlock -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -Y spinlock -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(grep -c -v spinlock "${result}")" != "0" ]; then
 		echo "[Fail] BPF result should not have non-spinlocks:" "$(cat "${result}")"
 		err=1
@@ -194,7 +194,7 @@ test_lock_filter()
 		return
 	fi
 
-	perf lock con -a -b -L tasklist_lock -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -L tasklist_lock -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(grep -c -v "${test_lock_filter_type}" "${result}")" != "0" ]; then
 		echo "[Fail] BPF result should not have non-${test_lock_filter_type} locks:" "$(cat "${result}")"
 		err=1
@@ -222,7 +222,7 @@ test_stack_filter()
 		return
 	fi
 
-	perf lock con -a -b -S unix_stream -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -S unix_stream -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result should have a lock from unix_stream:" "$(cat "${result}")"
 		err=1
@@ -250,7 +250,7 @@ test_aggr_task_stack_filter()
 		return
 	fi
 
-	perf lock con -a -b -t -S unix_stream -E 1 -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -t -S unix_stream -E 1 -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result should have a task from unix_stream:" "$(cat "${result}")"
 		err=1
@@ -266,15 +266,15 @@ test_cgroup_filter()
 		return
 	fi
 
-	perf lock con -a -b -g -E 1 -F wait_total -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -g -E 1 -F wait_total -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result should have a cgroup result:" "$(cat "${result}")"
 		err=1
 		exit
 	fi
 
 	cgroup=$(cat "${result}" | awk '{ print $3 }')
-	perf lock con -a -b -g -E 1 -G "${cgroup}" -q -- perf bench sched messaging > /dev/null 2> ${result}
+	perf lock con -a -b -g -E 1 -G "${cgroup}" -q -- perf bench sched messaging -p > /dev/null 2> ${result}
 	if [ "$(cat "${result}" | wc -l)" != "1" ]; then
 		echo "[Fail] BPF result should have a result with cgroup filter:" "$(cat "${cgroup}")"
 		err=1
@@ -309,7 +309,7 @@ test_csv_output()
 	fi
 
 	# the perf lock contention output goes to the stderr
-	perf lock con -a -b -E 1 -x , --output ${result} -- perf bench sched messaging > /dev/null 2>&1
+	perf lock con -a -b -E 1 -x , --output ${result} -- perf bench sched messaging -p > /dev/null 2>&1
 	output=$(grep -v "^#" ${result} | tr -d -c , | wc -c)
 	if [ "${header}" != "${output}" ]; then
 		echo "[Fail] BPF result does not match the number of commas: ${header} != ${output}"