[PATCH stalld 10/52] tests: Fix subshell swallowing test results

Test 5 in the starvation detection suite runs its assertions inside
a backgrounded subshell. The pass and fail functions increment the
TEST_PASSED and TEST_FAILED counters, but since those variables are
copied into the subshell, the increments are discarded when the child
exits. The test result is silently lost regardless of outcome.

Remove the subshell wrapper and run the test logic directly in the
main shell. Also replace the else branch, which logged informational
messages but never called pass or fail, with an actual check that
greps for the busy task PID in the starvation log to distinguish
false positives from unrelated starvation events.

Signed-off-by: Wander Lairson Costa <[email protected]>

Assisted-by: Claude Code:claude-opus-4-6[1m] [PAL]
Signed-off-by: Wander Lairson Costa <[email protected]>
---
 tests/functional/test_starvation_detection.sh | 35 ++++++++-----------
 1 file changed, 15 insertions(+), 20 deletions(-)

diff --git a/tests/functional/test_starvation_detection.sh b/tests/functional/test_starvation_detection.sh
index d8f874a..44024c7 100755
--- a/tests/functional/test_starvation_detection.sh
+++ b/tests/functional/test_starvation_detection.sh
@@ -241,31 +241,26 @@ start_stalld_with_log "${STALLD_LOG}" -f -v -l -t $threshold -c ${TEST_CPU} -a $
 # Create a task that gets CPU time but isn't starved
 # Use a SCHED_OTHER task with lower priority that still gets scheduled
 log "Creating a busy task that should NOT be starved"
-(
-    taskset -c ${TEST_CPU} bash -c 'for i in {1..100}; do sleep 0.1; done' &
-    BUSY_PID=$!
+taskset -c ${TEST_CPU} bash -c 'for i in {1..100}; do sleep 0.1; done' &
+BUSY_PID=$!
 
-    # Wait beyond threshold
-    sleep $((threshold + 3))
+# Wait beyond threshold
+sleep $((threshold + 3))
 
-    # Verify this task was NOT reported as starved
-    # Since it's making progress, stalld shouldn't detect it
-    if ! grep "starved" "${STALLD_LOG}"; then
-        pass "No false positive - task making progress not reported as starved"
+# Verify this task was NOT reported as starved
+# Since it's making progress, stalld shouldn't detect it
+if ! grep "starved" "${STALLD_LOG}"; then
+    pass "No false positive - task making progress not reported as starved"
+else
+    if grep "${BUSY_PID}" "${STALLD_LOG}" | grep -q "starved"; then
+        fail "False positive - progress-making task ${BUSY_PID} reported as starved"
     else
-        # Check if our specific task was reported
-        log "Log shows starvation, checking if it's our progress-making task..."
-        log "Log contents:"
-        cat "${STALLD_LOG}"
-        # This is not necessarily a failure - there might be other starved tasks
-        log "⚠ INFO: Starvation detected, but may be from other tasks"
+        pass "No false positive - starvation detected from other tasks, not ours"
     fi
+fi
 
-    kill ${BUSY_PID} 2>/dev/null
-    wait ${BUSY_PID} 2>/dev/null
-) &
-SUBSHELL_PID=$!
-wait ${SUBSHELL_PID}
+kill ${BUSY_PID} 2>/dev/null
+wait ${BUSY_PID} 2>/dev/null
 
 stop_stalld
 
-- 
2.54.0