test: Add test cases for queue-depth=1 FCFS perf optimization

t/Makefile.am

@@ -52,6 +52,7 @@ TESTS = \
     t2000-fcfs.t \
     t2001-fcfs-aware.t \
     t2002-easy.t \
+    t2003-fcfs-inorder.t \
     t3001-resource-basic.t \
     t3002-resource-prefix.t \
     t3003-resource-global.t \

t/t2003-fcfs-inorder.t

@@ -0,0 +1,50 @@
+#!/bin/bash
+#set -x
+
+test_description='Test fcfs scheduler with queue-depth=1 in simulator
+'
+
+# source sharness from the directore where this test
+# file resides
+#
+. $(dirname $0)/sharness.sh
+FLUX_MODULE_PATH="${SHARNESS_BUILD_DIRECTORY}/simulator/.libs:${FLUX_MODULE_PATH}"
+
+rdlconf=$(readlink -e "${SHARNESS_TEST_SRCDIR}/../conf/hype-io.lua")
+jobdata=$(readlink -e "${SHARNESS_TEST_SRCDIR}/data/job-traces/hype-test.csv")
+expected_order=$(readlink -e "${SHARNESS_TEST_SRCDIR}/data/emulator-data/fcfs_expected")
+
+#
+# print only with --debug
+#
+test_debug '
+	echo rdlconf=${rdlconf} &&
+    echo jobdata=${jobdata} &&
+    echo expected_order=${expected_order}
+'
+
+#
+# test_under_flux is under sharness.d/
+#
+test_under_flux 1
+
+test_expect_success 'sim: started successfully with queue-depth=1' '
+    adjust_session_info 12 &&
+    timed_wait_job 5 &&
+    flux module load sim exit-on-complete=false &&
+    flux module load submit job-csv=${jobdata} &&
+    flux module load sim_exec &&
+	flux module load sched rdl-conf=${rdlconf} in-sim=true plugin=sched.fcfs sched-params=queue-depth=1
+'
+
+test_expect_success 'sim: scheduled and ran all jobs with queue-depth=1' '
+    timed_sync_wait_job 60
+'
+
+for x in $(seq 1 12); do echo "$x $(flux kvs get $(job_kvs_path $x).starting_time)"; done | sort -k 2n -k 1n | cut -d ' ' -f 1 > actual
+
+test_expect_success 'jobs scheduled in correct order with queue-depth=1' '
+    diff -u ${expected_order} ./actual
+'
+
+test_done