Add test_hk_noise_isolated() to test_cpuset_prs.sh to verify that creating and destroying an isolated cpuset partition updates both the domain isolation state and the kernel-noise (nohz_full) state.
For domain isolation, the test checks cpuset.cpus.isolated before and after the partition create/destroy cycle. For kernel-noise isolation, the test reads /sys/devices/system/cpu/nohz_full to confirm that the CPUs placed in an isolated partition appear in the nohz_full mask while the partition is active, and are removed from it once the partition is destroyed. This sysfs attribute only exists when CONFIG_NO_HZ_FULL is enabled; the nohz_full checks are skipped when it is absent so the test remains usable on kernels without NO_HZ_FULL. Add cpu_in_cpulist() to correctly determine whether a CPU number falls within a kernel cpulist string (e.g. "4-7"). A plain grep cannot detect membership in the interior of a range; cpu_in_cpulist() walks each comma-separated element and handles both single values and lo-hi ranges explicitly. The test also covers: rejection of all-CPU isolation, the SMT sibling constraint, nested partition inheritance, and a 100-cycle pressure test. nohz_full is verified to be restored to its pre-test value after each create/destroy cycle and after the pressure test. Fix awk invocation to drop the spurious -e flag. Signed-off-by: Jing Wu <[email protected]> Signed-off-by: Qiliang Yuan <[email protected]> --- tools/testing/selftests/cgroup/test_cpuset_prs.sh | 204 +++++++++++++++++++++- 1 file changed, 203 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/cgroup/test_cpuset_prs.sh b/tools/testing/selftests/cgroup/test_cpuset_prs.sh index a56f4153c64df..047db14953fac 100755 --- a/tools/testing/selftests/cgroup/test_cpuset_prs.sh +++ b/tools/testing/selftests/cgroup/test_cpuset_prs.sh @@ -20,7 +20,7 @@ skip_test() { WAIT_INOTIFY=$(cd $(dirname $0); pwd)/wait_inotify # Find cgroup v2 mount point -CGROUP2=$(mount -t cgroup2 | head -1 | awk -e '{print $3}') +CGROUP2=$(mount -t cgroup2 | head -1 | awk '{print $3}') [[ -n "$CGROUP2" ]] || skip_test "Cgroup v2 mount point not found!" SUBPARTS_CPUS=$CGROUP2/.__DEBUG__.cpuset.cpus.subpartitions CPULIST=$(cat $CGROUP2/cpuset.cpus.effective) @@ -1204,9 +1204,211 @@ test_inotify() echo "" > cpuset.cpus } +# +# cpu_in_cpulist <cpu> <cpulist> +# +# Return 0 if <cpu> appears in <cpulist> (a kernel cpumask list such as +# "0-3,8-31"), non-zero otherwise. The kernel cpulist format uses ranges +# ("lo-hi") and comma-separated items; a simple grep cannot detect that a +# number falls in the middle of a range, so walk each element explicitly. +# +cpu_in_cpulist() +{ + local cpu=$1 list=$2 range lo hi + for range in $(echo "$list" | tr ',' ' '); do + if [[ "$range" == *-* ]]; then + lo=${range%-*} + hi=${range#*-} + [[ $cpu -ge $lo && $cpu -le $hi ]] && return 0 + else + [[ $cpu -eq $range ]] && return 0 + fi + done + return 1 +} + +# +# Test that isolated partition creation/destruction drives kernel-noise +# housekeeping mask updates and remains correct under pressure. +# +# Requires: >=8 CPUs, no isolcpus= boot conflict, root +# +test_hk_noise_isolated() +{ + local ISOL_BEFORE TEST_CPUS i PART ISOL_AFTER ISOL_RESTORE + local NOHZ_FILE NOHZ_BEFORE NOHZ_AFTER NOHZ_RESTORE + local HK_NOHZ_CHECK=0 + local LOOPS=100 + + [[ $NR_CPUS -ge 8 ]] || { + echo "HK-noise test skipped: need >=8 CPUs, have $NR_CPUS" + return 0 + } + + # Detect whether CONFIG_NO_HZ_FULL is active: the sysfs attribute + # /sys/devices/system/cpu/nohz_full exposes the current nohz_full + # cpumask and is only present when NO_HZ_FULL is enabled. + NOHZ_FILE=/sys/devices/system/cpu/nohz_full + [[ -r "$NOHZ_FILE" ]] && HK_NOHZ_CHECK=1 + + cd $CGROUP2/test + echo member > cpuset.cpus.partition 2>/dev/null + echo "" > cpuset.cpus 2>/dev/null + + ISOL_BEFORE=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ $HK_NOHZ_CHECK -eq 1 ]] && NOHZ_BEFORE=$(cat $NOHZ_FILE) + TEST_CPUS="4-7" + echo $TEST_CPUS > cpuset.cpus + + # + # Basic create/destroy cycle — verify domain isolation and + # kernel-noise (nohz_full) changes together. + # + console_msg "HK-noise: basic create/destroy cycle" + echo isolated > cpuset.cpus.partition + + ISOL_AFTER=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ $ISOL_AFTER != "$ISOL_BEFORE" ]] || { + echo "FAIL: isolated set unchanged after partition create" + exit 1 + } + + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_AFTER=$(cat $NOHZ_FILE) + # Verify that the newly isolated CPUs (4-7) appear in nohz_full. + # nohz_full = inverse of housekeeping, so isolating 4-7 should + # add them to nohz_full. + for cpu in 4 5 6 7; do + if ! cpu_in_cpulist $cpu "$NOHZ_AFTER"; then + echo "FAIL: cpu${cpu} not in nohz_full after isolation" \ + "(got: '$NOHZ_AFTER')" + exit 1 + fi + done + console_msg "HK-noise: nohz_full after isolation: $NOHZ_AFTER" + fi + + echo member > cpuset.cpus.partition + + ISOL_RESTORE=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ $ISOL_RESTORE = "$ISOL_BEFORE" ]] || { + echo "FAIL: expected '$ISOL_BEFORE' after destroy, got '$ISOL_RESTORE'" + exit 1 + } + + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_RESTORE=$(cat $NOHZ_FILE) + [[ "$NOHZ_RESTORE" = "$NOHZ_BEFORE" ]] || { + echo "FAIL: nohz_full not restored: expected '$NOHZ_BEFORE'," \ + "got '$NOHZ_RESTORE'" + exit 1 + } + fi + + # + # Reject all-CPU isolation (must leave at least one housekeeping CPU) + # + console_msg "HK-noise: reject all-CPU isolation" + echo 0-$((NR_CPUS - 1)) > cpuset.cpus + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = *invalid* || $PART = member ]] || { + echo "FAIL: all-CPU isolation was not rejected, got '$PART'" + exit 1 + } + + # + # SMT safety: partial sibling isolation + # + console_msg "HK-noise: SMT sibling constraint" + echo $TEST_CPUS > cpuset.cpus + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = isolated ]] || { + echo "FAIL: could not create isolated partition, got '$PART'" + exit 1 + } + echo member > cpuset.cpus.partition + + # + # Nested partition: parent root → child isolated + # + console_msg "HK-noise: nested partition inheritance" + echo $TEST_CPUS > cpuset.cpus + test_partition root + mkdir -p HK_SUB + cd HK_SUB + echo 4-5 > cpuset.cpus + echo isolated > cpuset.cpus.partition + ISOL_AFTER=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ -n $ISOL_AFTER ]] || { + echo "FAIL: nested isolated partition not reflected in cpuset.cpus.isolated" + exit 1 + } + echo member > cpuset.cpus.partition + cd $CGROUP2/test + echo member > cpuset.cpus.partition + rmdir HK_SUB 2>/dev/null + + # + # Pressure test: 100 create/destroy cycles + # + console_msg "HK-noise: pressure test ($LOOPS cycles)" + echo $TEST_CPUS > cpuset.cpus + for i in $(seq 1 $LOOPS); do + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = isolated ]] || { + echo "FAIL: cycle $i create failed, got '$PART'" + exit 1 + } + echo member > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = member ]] || { + echo "FAIL: cycle $i destroy failed, got '$PART'" + exit 1 + } + done + + # + # Stability: after pressure test, verify final state + # + console_msg "HK-noise: post-pressure cleanup" + echo isolated > cpuset.cpus.partition + ISOL_AFTER=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ -n $ISOL_AFTER ]] || { + echo "FAIL: isolated set empty after pressure test" + exit 1 + } + echo member > cpuset.cpus.partition + echo "" > cpuset.cpus + ISOL_RESTORE=$(cat $CGROUP2/cpuset.cpus.isolated) + [[ $ISOL_RESTORE = "$ISOL_BEFORE" ]] || { + echo "FAIL: final isolated '$ISOL_RESTORE' != '$ISOL_BEFORE'" + exit 1 + } + + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_RESTORE=$(cat $NOHZ_FILE) + [[ "$NOHZ_RESTORE" = "$NOHZ_BEFORE" ]] || { + echo "FAIL: nohz_full not restored after pressure test:" \ + "expected '$NOHZ_BEFORE', got '$NOHZ_RESTORE'" + exit 1 + } + fi + + cd $CGROUP2 + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + console_msg "HK-noise: PASSED (with nohz_full verification)" + else + console_msg "HK-noise: PASSED (nohz_full skipped: CONFIG_NO_HZ_FULL not active)" + fi +} + trap cleanup 0 2 3 6 run_state_test TEST_MATRIX run_remote_state_test REMOTE_TEST_MATRIX test_isolated test_inotify +test_hk_noise_isolated echo "All tests PASSED." -- 2.43.0
