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Thu, 09 Jul 2026 20:30:04 -0700 (PDT) From: Jing Wu Date: Fri, 10 Jul 2026 11:28:22 +0800 Subject: [PATCH v4 11/11] selftests/cgroup: add kernel-noise isolation test to cpuset selftest Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260710-wujing-dhm-v4-11-2e912e5d9645@gmail.com> References: <20260710-wujing-dhm-v4-0-2e912e5d9645@gmail.com> In-Reply-To: <20260710-wujing-dhm-v4-0-2e912e5d9645@gmail.com> To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Anna-Maria Behnsen , Tejun Heo , Jonathan Corbet , Shuah Khan , Shuah Khan , Thomas Gleixner Cc: Waiman Long , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Jing Wu , Qiliang Yuan X-Mailer: b4 0.13.0 Add test_hk_noise_isolated() to test_cpuset_prs.sh to verify that creating and destroying an isolated partition updates the kernel-noise housekeeping state, including the /sys/devices/system/cpu/nohz_full attribute. Add the cpu_in_cpulist() helper to correctly test membership against a cpulist that may contain ranges. Also detect and report whether the test is running in zero-boot-param mode (no nohz_full= in /proc/cmdline). When in zero-boot-param mode the test confirms that nohz_full is activated by the DHM runtime path, verifying that dhm_cycle_isolated_cpus() correctly enables tick isolation without any boot-time setup. Co-developed-by: Qiliang Yuan Signed-off-by: Qiliang Yuan Signed-off-by: Jing Wu --- tools/testing/selftests/cgroup/test_cpuset_prs.sh | 580 +++++++++++++++++++++- 1 file changed, 579 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..ce16734545505 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 +1204,587 @@ test_inotify() echo "" > cpuset.cpus } +# +# cpu_in_cpulist +# +# Return 0 if appears in (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 +} + +# +# verify_nohz_exact +# +# Verify that nohz_full equals ∪ . +# may be a cpulist range ("4-7") or empty string (""). +# Catches both missing CPUs and unexpected extra CPUs. +# +verify_nohz_exact() +{ + local baseline=$1 active=$2 current=$3 cpu exp got + for cpu in $(seq 0 $((NR_CPUS - 1))); do + exp=0; got=0 + cpu_in_cpulist $cpu "$baseline" && exp=1 + [[ -n "$active" ]] && cpu_in_cpulist $cpu "$active" && exp=1 + cpu_in_cpulist $cpu "$current" && got=1 + [[ $exp -eq $got ]] || { + if [[ $got -eq 0 ]]; then + echo "FAIL: cpu${cpu} expected in nohz_full but absent" \ + "(baseline='$baseline' active='$active'" \ + "current='$current')" + else + echo "FAIL: cpu${cpu} unexpectedly in nohz_full" \ + "(baseline='$baseline' active='$active'" \ + "current='$current')" + fi + return 1 + } + done + return 0 +} + +# +# 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 +# + +# +# hk_noise_check_nocb_affinity +# +# When expect_isolated=1: verify rcuop/N kthreads for CPUs in cpulist do NOT +# include those CPUs in their scheduler affinity (RCU NOCB active — callbacks +# for the isolated CPU are offloaded to a different CPU). +# When expect_isolated=0: verify CPUs are back in affinity (NOCB restored). +# Silently skips CPUs whose rcuop/N thread is absent (no NOCB support). +# +hk_noise_check_nocb_affinity() +{ + local cpulist=$1 expect_isolated=$2 + local cpu lo hi range pid aff_hex rev_hex nibble_pos nibble_char + local nibble_val bit_in_nibble bit failed=0 + + command -v taskset > /dev/null 2>&1 || return 0 + + for range in $(echo "$cpulist" | tr ',' ' '); do + if [[ "$range" == *-* ]]; then + lo=${range%-*}; hi=${range#*-} + else + lo=$range; hi=$range + fi + for cpu in $(seq "$lo" "$hi"); do + pid=$(ps -eo pid,comm | awk -v c="rcuop/$cpu" '$2==c{print $1}') + [[ -n "$pid" ]] || continue + aff_hex=$(taskset -p "$pid" 2>/dev/null | awk '{print $NF}') + [[ -n "$aff_hex" ]] || continue + + # Extract bit from the hex affinity mask. + # Each hex digit covers 4 CPUs; reverse the string to + # work from the LSB side. + rev_hex=$(echo "$aff_hex" | rev) + nibble_pos=$((cpu / 4)) + nibble_char=${rev_hex:$nibble_pos:1} + if [[ -z "$nibble_char" ]]; then + nibble_val=0 + else + nibble_val=$((16#$nibble_char)) + fi + bit_in_nibble=$((cpu % 4)) + bit=$(( (nibble_val >> bit_in_nibble) & 1 )) + + if [[ $expect_isolated -eq 1 && $bit -eq 1 ]]; then + echo "FAIL: rcuop/$cpu affinity still includes" \ + "CPU$cpu after isolation (mask=0x$aff_hex)" + failed=1 + elif [[ $expect_isolated -eq 0 && $bit -eq 0 ]]; then + echo "FAIL: rcuop/$cpu affinity still excludes" \ + "CPU$cpu after de-isolation (mask=0x$aff_hex)" + failed=1 + fi + done + done + return $failed +} + +test_hk_noise_isolated() +{ + local ISOL_BEFORE TEST_CPUS i PART ISOL_AFTER ISOL_RESTORE + local NOHZ_FILE NOHZ_BEFORE NOHZ_AFTER NOHZ_RESTORE + local HK_NOHZ_CHECK=0 + local LOOPS=100 + local CMDLINE HAS_BOOT_NOHZ=0 + local DMESG_LINES_START + DMESG_LINES_START=$(dmesg | wc -l) + + [[ $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 + + # Determine if running in zero-boot-param mode. DHM activates tick + # and RCU-NOCB isolation at runtime; no nohz_full= or rcu_nocbs= + # kernel boot parameters are required. + { read -r CMDLINE < /proc/cmdline; } 2>/dev/null || CMDLINE="" + [[ $CMDLINE = *nohz_full=* ]] && HAS_BOOT_NOHZ=1 + if [[ $HAS_BOOT_NOHZ -eq 0 ]]; then + console_msg "HK-noise: zero-boot-param mode" \ + "(no nohz_full= in /proc/cmdline -- testing DHM runtime path)" + else + console_msg "HK-noise: boot-param mode (nohz_full= present at boot)" + fi + + 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 $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$TEST_CPUS" "$NOHZ_AFTER" || exit 1 + console_msg "HK-noise: nohz_full after isolation: $NOHZ_AFTER" + fi + + # Verify RCU NOCB: rcuop/N kthreads for isolated CPUs must have those + # CPUs removed from their scheduler affinity mask. + hk_noise_check_nocb_affinity "$TEST_CPUS" 1 || exit 1 + + 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 $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "" "$NOHZ_RESTORE" || exit 1 + fi + + # Verify RCU NOCB restored: isolated CPUs must reappear in rcuop/N affinity. + hk_noise_check_nocb_affinity "$TEST_CPUS" 0 || exit 1 + + # + # 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 + + # + # Non-hotpluggable CPU: must be skipped with a kernel warning without + # rejecting the partition; hotpluggable peers must still be isolated. + # + # A CPU whose online file is absent (e.g. CPU 0 on x86-64) has hotplug + # disabled. DHM emits pr_warn_once and keeps it in the tick/RCU-NOCB + # housekeeping set; it must not appear in nohz_full after isolation. + # The remaining hotpluggable CPUs in the partition must still be isolated. + # + local FIXED_CPU="" c NOHZ_NOW + for c in $(seq 0 $((NR_CPUS - 1))); do + [[ -f /sys/devices/system/cpu/cpu${c}/online ]] || { + FIXED_CPU=$c + break + } + done + if [[ -n "$FIXED_CPU" ]]; then + console_msg "HK-noise: non-hotpluggable CPU${FIXED_CPU} skip" + echo "${FIXED_CPU},${TEST_CPUS}" > cpuset.cpus + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = isolated ]] || { + echo "FAIL: partition rejected when including non-hotpluggable" \ + "CPU${FIXED_CPU}: got '$PART'" + exit 1 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + if cpu_in_cpulist $FIXED_CPU "$NOHZ_NOW"; then + echo "FAIL: non-hotpluggable CPU${FIXED_CPU} appeared" \ + "in nohz_full (should be skipped)" + exit 1 + fi + local lo hi + lo=${TEST_CPUS%%-*} + hi=${TEST_CPUS##*-} + for cpu in $(seq "$lo" "$hi"); do + if ! cpu_in_cpulist $cpu "$NOHZ_NOW"; then + echo "FAIL: hotpluggable cpu${cpu} missing from" \ + "nohz_full in mixed partition (got: '$NOHZ_NOW')" + exit 1 + fi + done + console_msg "HK-noise: CPU${FIXED_CPU} absent, ${TEST_CPUS} present" \ + "in nohz_full: $NOHZ_NOW" + fi + echo member > cpuset.cpus.partition + echo $TEST_CPUS > cpuset.cpus + else + console_msg "HK-noise: all CPUs hotpluggable; skip non-hotpluggable subtest" + fi + + # + # Delta isolation: modify cpuset.cpus while the partition is isolated. + # dhm_prev_isolated must track the delta and update nohz_full in step. + # + local lo hi mid lower_cpus upper_cpu + lo=${TEST_CPUS%%-*} + hi=${TEST_CPUS##*-} + mid=$(( lo + (hi - lo) / 2 )) + lower_cpus="${lo}-${mid}" + upper_cpu=$(( mid + 1 )) + console_msg "HK-noise: delta isolation (shrink ${TEST_CPUS} → ${lower_cpus})" + echo $TEST_CPUS > cpuset.cpus + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = isolated ]] || { + echo "FAIL: delta test: initial isolation failed, got '$PART'" + exit 1 + } + echo $lower_cpus > cpuset.cpus + PART=$(cat cpuset.cpus.partition) + if [[ $PART = isolated ]]; then + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$lower_cpus" "$NOHZ_NOW" || exit 1 + fi + # Expand back to full TEST_CPUS and re-verify + echo $TEST_CPUS > cpuset.cpus + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$TEST_CPUS" "$NOHZ_NOW" || exit 1 + fi + echo member > cpuset.cpus.partition + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "" "$NOHZ_NOW" || exit 1 + fi + else + console_msg "HK-noise: delta test: partition invalidated on shrink" \ + "('$PART') -- cpuset constraint, not a DHM bug; skipping" + echo member > cpuset.cpus.partition 2>/dev/null || true + fi + echo $TEST_CPUS > cpuset.cpus + + # + # Nested partition: parent root → child isolated + # + console_msg "HK-noise: nested partition inheritance" + echo $TEST_CPUS > cpuset.cpus + test_partition root + mkdir -p HK_SUB + cd HK_SUB + echo "${lo}-$((lo + 1))" > cpuset.cpus + echo isolated > cpuset.cpus.partition + ISOL_AFTER=$(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 $CGROUP2/test + echo member > cpuset.cpus.partition + rmdir HK_SUB 2>/dev/null + + # + # Pressure test: 100 create/destroy cycles with nohz_full verified + # on every cycle to catch mid-run state corruption. + # + console_msg "HK-noise: pressure test ($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 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$TEST_CPUS" "$NOHZ_NOW" || { + echo "FAIL: nohz_full wrong at cycle $i (isolated)" + exit 1 + } + fi + echo member > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = member ]] || { + echo "FAIL: cycle $i destroy failed, got '$PART'" + exit 1 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "" "$NOHZ_NOW" || { + echo "FAIL: nohz_full wrong at cycle $i (member)" + exit 1 + } + fi + done + + # + # Stability: after pressure test, verify final state + # + console_msg "HK-noise: post-pressure cleanup" + echo isolated > cpuset.cpus.partition + ISOL_AFTER=$(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 '$NOHZ_RESTORE'" + exit 1 + } + fi + + # + # Pressure with resident task: create/destroy cycles while a sleeping + # task occupies the isolated partition. Exercises the dhm_cycling_cpus + # suppression path that prevents false partition invalidation when a + # task is present during hotplug cycling steps. + # + console_msg "HK-noise: pressure with resident task ($LOOPS cycles)" + echo $TEST_CPUS > cpuset.cpus + sleep 600 & + local TASK_PID=$! + echo $TASK_PID > cgroup.procs + for i in $(seq 1 $LOOPS); do + echo isolated > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = isolated ]] || { + echo "FAIL: task-occupied cycle $i create failed, got '$PART'" + kill $TASK_PID 2>/dev/null; wait $TASK_PID 2>/dev/null + exit 1 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$TEST_CPUS" "$NOHZ_NOW" || { + kill $TASK_PID 2>/dev/null; wait $TASK_PID 2>/dev/null + exit 1 + } + fi + echo member > cpuset.cpus.partition + PART=$(cat cpuset.cpus.partition) + [[ $PART = member ]] || { + echo "FAIL: task-occupied cycle $i destroy failed, got '$PART'" + kill $TASK_PID 2>/dev/null; wait $TASK_PID 2>/dev/null + exit 1 + } + done + kill $TASK_PID 2>/dev/null + wait $TASK_PID 2>/dev/null + echo "" > cpuset.cpus + + # + # Concurrent partitions: two sibling cgroups each holding half of + # TEST_CPUS simultaneously isolated. Verifies independent isolation + # and correct union in cpuset.cpus.isolated / nohz_full. + # + local lo hi mid lower_half upper_half NOHZ_BOTH + lo=${TEST_CPUS%%-*}; hi=${TEST_CPUS##*-} + mid=$(( lo + (hi - lo) / 2 )) + lower_half="${lo}-${mid}" + upper_half="$((mid + 1))-${hi}" + console_msg "HK-noise: concurrent partitions ($lower_half and $upper_half)" + echo $TEST_CPUS > cpuset.cpus + echo root > cpuset.cpus.partition + mkdir -p HK_A HK_B + echo "$lower_half" > HK_A/cpuset.cpus + echo isolated > HK_A/cpuset.cpus.partition + echo "$upper_half" > HK_B/cpuset.cpus + echo isolated > HK_B/cpuset.cpus.partition + local PA PB + PA=$(cat HK_A/cpuset.cpus.partition) + PB=$(cat HK_B/cpuset.cpus.partition) + [[ $PA = isolated ]] || { + echo "FAIL: concurrent partition HK_A not isolated, got '$PA'" + echo member > HK_A/cpuset.cpus.partition 2>/dev/null + echo member > HK_B/cpuset.cpus.partition 2>/dev/null + rmdir HK_A HK_B 2>/dev/null + echo member > cpuset.cpus.partition 2>/dev/null + exit 1 + } + [[ $PB = isolated ]] || { + echo "FAIL: concurrent partition HK_B not isolated, got '$PB'" + echo member > HK_A/cpuset.cpus.partition 2>/dev/null + echo member > HK_B/cpuset.cpus.partition 2>/dev/null + rmdir HK_A HK_B 2>/dev/null + echo member > cpuset.cpus.partition 2>/dev/null + exit 1 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_BOTH=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "$TEST_CPUS" "$NOHZ_BOTH" || { + echo member > HK_A/cpuset.cpus.partition 2>/dev/null + echo member > HK_B/cpuset.cpus.partition 2>/dev/null + rmdir HK_A HK_B 2>/dev/null + echo member > cpuset.cpus.partition 2>/dev/null + exit 1 + } + fi + hk_noise_check_nocb_affinity "$TEST_CPUS" 1 || { + echo member > HK_A/cpuset.cpus.partition 2>/dev/null + echo member > HK_B/cpuset.cpus.partition 2>/dev/null + rmdir HK_A HK_B 2>/dev/null + echo member > cpuset.cpus.partition 2>/dev/null + exit 1 + } + echo member > HK_A/cpuset.cpus.partition + echo member > HK_B/cpuset.cpus.partition + rmdir HK_A HK_B + echo member > cpuset.cpus.partition + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "" "$NOHZ_NOW" || exit 1 + fi + hk_noise_check_nocb_affinity "$TEST_CPUS" 0 || exit 1 + echo "" > cpuset.cpus + + # + # Concurrent create/destroy: two background subshells race on the same + # partition simultaneously. Verifies that concurrent cpuset writes + # do not corrupt kernel state or trigger warnings. + # + console_msg "HK-noise: concurrent create/destroy race" + echo $TEST_CPUS > cpuset.cpus + local RACE_LOOPS=30 RACE_PID1 RACE_PID2 + (for i in $(seq 1 $RACE_LOOPS); do + echo isolated > cpuset.cpus.partition 2>/dev/null + echo member > cpuset.cpus.partition 2>/dev/null + done) & + RACE_PID1=$! + (for i in $(seq 1 $RACE_LOOPS); do + echo member > cpuset.cpus.partition 2>/dev/null + echo isolated > cpuset.cpus.partition 2>/dev/null + done) & + RACE_PID2=$! + wait $RACE_PID1 $RACE_PID2 + # Drive to a known-good state regardless of who won the last write. + echo member > cpuset.cpus.partition 2>/dev/null || true + PART=$(cat cpuset.cpus.partition) + [[ $PART = member ]] || { + echo "FAIL: concurrent race left partition in bad state: '$PART'" + exit 1 + } + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + NOHZ_NOW=$(cat $NOHZ_FILE) + verify_nohz_exact "$NOHZ_BEFORE" "" "$NOHZ_NOW" || exit 1 + fi + echo "" > cpuset.cpus + + # + # Kernel hard-error check: none of the above scenarios must have + # triggered a BUG, OOPS, panic, or RCU stall in the kernel log. + # Also catch WARNINGs that implicate our subsystems (cpuset / rcu / + # nohz / housekeeping / irq_affinity); ignore unrelated WARNINGs from + # other kernel subsystems or user-space processes. + # + console_msg "HK-noise: checking kernel log for errors" + local new_errors + new_errors=$(dmesg | tail -n "+$((DMESG_LINES_START + 1))" | \ + grep -c -E \ + 'kernel BUG at|OOPS|Kernel panic|RCU Stall|scheduling while atomic' \ + || true) + local new_subsys_warns + new_subsys_warns=$(dmesg | tail -n "+$((DMESG_LINES_START + 1))" | \ + grep 'WARNING:' | \ + grep -c -E 'cpuset|rcu|nohz|housekeeping|irq_affinity|dhm' \ + || true) + local total_errors=$(( new_errors + new_subsys_warns )) + [[ $total_errors -eq 0 ]] || { + echo "FAIL: $total_errors kernel error(s)/warning(s) during HK-noise test:" + dmesg | tail -n "+$((DMESG_LINES_START + 1))" | \ + grep -E 'kernel BUG at|OOPS|Kernel panic|RCU Stall|scheduling while atomic' | head -10 + dmesg | tail -n "+$((DMESG_LINES_START + 1))" | \ + grep 'WARNING:' | grep -E 'cpuset|rcu|nohz|housekeeping|irq_affinity|dhm' | head -10 + exit 1 + } + + cd $CGROUP2 + if [[ $HK_NOHZ_CHECK -eq 1 ]]; then + if [[ $HAS_BOOT_NOHZ -eq 0 ]]; then + console_msg "HK-noise: PASSED" \ + "(zero-boot-param: nohz_full verified via DHM runtime path)" + else + console_msg "HK-noise: PASSED (with nohz_full verification)" + fi + 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