From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- tools/testing/selftests/verification/.gitignore | 2 + tools/testing/selftests/verification/Makefile | 8 +++ tools/testing/selftests/verification/config | 1 + tools/testing/selftests/verification/settings | 1 + .../selftests/verification/test.d/functions | 39 +++++++++++ .../test.d/rv_monitor_enable_disable.tc | 75 ++++++++++++++++++++++ .../verification/test.d/rv_monitor_reactor.tc | 68 ++++++++++++++++++++ .../verification/test.d/rv_monitors_available.tc | 18 ++++++ .../verification/test.d/rv_wwnr_printk.tc | 30 +++++++++ .../selftests/verification/verificationtest-ktap | 8 +++ 10 files changed, 250 insertions(+) create mode 100644 tools/testing/selftests/verification/.gitignore create mode 100644 tools/testing/selftests/verification/Makefile create mode 100644 tools/testing/selftests/verification/config create mode 100644 tools/testing/selftests/verification/settings create mode 100644 tools/testing/selftests/verification/test.d/functions create mode 100644 tools/testing/selftests/verification/test.d/rv_monitor_enable_disable.tc create mode 100644 tools/testing/selftests/verification/test.d/rv_monitor_reactor.tc create mode 100644 tools/testing/selftests/verification/test.d/rv_monitors_available.tc create mode 100644 tools/testing/selftests/verification/test.d/rv_wwnr_printk.tc create mode 100755 tools/testing/selftests/verification/verificationtest-ktap (limited to 'tools/testing/selftests/verification') diff --git a/tools/testing/selftests/verification/.gitignore b/tools/testing/selftests/verification/.gitignore new file mode 100644 index 000000000..2659417cb --- /dev/null +++ b/tools/testing/selftests/verification/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +logs diff --git a/tools/testing/selftests/verification/Makefile b/tools/testing/selftests/verification/Makefile new file mode 100644 index 000000000..aa8790c22 --- /dev/null +++ b/tools/testing/selftests/verification/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +all: + +TEST_PROGS := verificationtest-ktap +TEST_FILES := test.d settings +EXTRA_CLEAN := $(OUTPUT)/logs/* + +include ../lib.mk diff --git a/tools/testing/selftests/verification/config b/tools/testing/selftests/verification/config new file mode 100644 index 000000000..43072c1c3 --- /dev/null +++ b/tools/testing/selftests/verification/config @@ -0,0 +1 @@ +CONFIG_RV=y diff --git a/tools/testing/selftests/verification/settings b/tools/testing/selftests/verification/settings new file mode 100644 index 000000000..e7b941753 --- /dev/null +++ b/tools/testing/selftests/verification/settings @@ -0,0 +1 @@ +timeout=0 diff --git a/tools/testing/selftests/verification/test.d/functions b/tools/testing/selftests/verification/test.d/functions new file mode 100644 index 000000000..ec36a092f --- /dev/null +++ b/tools/testing/selftests/verification/test.d/functions @@ -0,0 +1,39 @@ +check_requires() { # Check required files, monitors and reactors + for i in "$@" ; do + p=${i%:program} + m=${i%:monitor} + r=${i%:reactor} + if [ $p != $i ]; then + if ! which $p ; then + echo "Required program $p is not found." + exit_unresolved + fi + elif [ $m != $i ]; then + if ! grep -wq $m available_monitors ; then + echo "Required monitor $m is not configured." + exit_unsupported + fi + elif [ $r != $i ]; then + if ! grep -wq $r available_reactors ; then + echo "Required reactor $r is not configured." + exit_unsupported + fi + elif [ ! -e $i ]; then + echo "Required feature interface $i doesn't exist." + exit_unsupported + fi + done +} + +initialize_system() { # Reset RV to initial-state + echo > enabled_monitors + for m in monitors/*; do + echo nop > $m/reactors || true + done + echo 1 > monitoring_on + echo 1 > reacting_on || true +} + +finish_system() { + initialize_system +} diff --git a/tools/testing/selftests/verification/test.d/rv_monitor_enable_disable.tc b/tools/testing/selftests/verification/test.d/rv_monitor_enable_disable.tc new file mode 100644 index 000000000..f29236def --- /dev/null +++ b/tools/testing/selftests/verification/test.d/rv_monitor_enable_disable.tc @@ -0,0 +1,75 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# description: Test monitor enable/disable + +test_simple_monitor() { + local monitor="$1" + local prefix="$2" # nested monitors + + echo 1 > "monitors/$prefix$monitor/enable" + grep -q "$monitor$" enabled_monitors + + echo 0 > "monitors/$prefix$monitor/enable" + ! grep -q "$monitor$" enabled_monitors + + echo "$monitor" >> enabled_monitors + grep -q 1 "monitors/$prefix$monitor/enable" + + echo "!$monitor" >> enabled_monitors + grep -q 0 "monitors/$prefix$monitor/enable" +} + +test_container_monitor() { + local monitor="$1" + local nested + + echo 1 > "monitors/$monitor/enable" + grep -q "^$monitor$" enabled_monitors + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + grep -q "^$monitor:$nested$" enabled_monitors + done + test -n "$nested" + + echo 0 > "monitors/$monitor/enable" + ! grep -q "^$monitor$" enabled_monitors + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + ! grep -q "^$monitor:$nested$" enabled_monitors + done + + echo "$monitor" >> enabled_monitors + grep -q 1 "monitors/$monitor/enable" + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + grep -q "^$monitor:$nested$" enabled_monitors + done + + echo "!$monitor" >> enabled_monitors + grep -q 0 "monitors/$monitor/enable" + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + test_simple_monitor "$nested" "$monitor/" + done +} + +for monitor_dir in monitors/*; do + monitor=$(basename "$monitor_dir") + + if find "$monitor_dir" -mindepth 1 -type d | grep -q .; then + test_container_monitor "$monitor" + else + test_simple_monitor "$monitor" + fi +done + +! echo non_existent_monitor > enabled_monitors +! grep -q "^non_existent_monitor$" enabled_monitors diff --git a/tools/testing/selftests/verification/test.d/rv_monitor_reactor.tc b/tools/testing/selftests/verification/test.d/rv_monitor_reactor.tc new file mode 100644 index 000000000..2958bf849 --- /dev/null +++ b/tools/testing/selftests/verification/test.d/rv_monitor_reactor.tc @@ -0,0 +1,68 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# description: Test monitor reactor setting +# requires: available_reactors + +test_monitor_reactor() { + local monitor="$1" + local prefix="$2" # nested monitors + + while read -r reactor; do + [ "$reactor" = nop ] && continue + + echo "$reactor" > "monitors/$prefix$monitor/reactors" + grep -q "\\[$reactor\\]" "monitors/$prefix$monitor/reactors" + done < available_reactors + + echo nop > "monitors/$prefix$monitor/reactors" + grep -q "\\[nop\\]" "monitors/$prefix$monitor/reactors" +} + +test_container_monitor() { + local monitor="$1" + local nested + + while read -r reactor; do + [ "$reactor" = nop ] && continue + + echo "$reactor" > "monitors/$monitor/reactors" + grep -q "\\[$reactor\\]" "monitors/$monitor/reactors" + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + grep -q "\\[$reactor\\]" "monitors/$monitor/$nested/reactors" + done + done < available_reactors + test -n "$nested" + + echo nop > "monitors/$monitor/reactors" + grep -q "\\[nop\\]" "monitors/$monitor/reactors" + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + grep -q "\\[nop\\]" "monitors/$monitor/$nested/reactors" + done + + for nested_dir in "monitors/$monitor"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + test_monitor_reactor "$nested" "$monitor/" + done +} + +for monitor_dir in monitors/*; do + monitor=$(basename "$monitor_dir") + + if find "$monitor_dir" -mindepth 1 -type d | grep -q .; then + test_container_monitor "$monitor" + else + test_monitor_reactor "$monitor" + fi +done + +monitor=$(ls /sys/kernel/tracing/rv/monitors -1 | head -n 1) +test -f "monitors/$monitor/reactors" +! echo non_existent_reactor > "monitors/$monitor/reactors" +! grep -q "\\[non_existent_reactor\\]" "monitors/$monitor/reactors" diff --git a/tools/testing/selftests/verification/test.d/rv_monitors_available.tc b/tools/testing/selftests/verification/test.d/rv_monitors_available.tc new file mode 100644 index 000000000..e6a4a1410 --- /dev/null +++ b/tools/testing/selftests/verification/test.d/rv_monitors_available.tc @@ -0,0 +1,18 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# description: Check available monitors + +for monitor_dir in monitors/*; do + monitor=$(basename "$monitor_dir") + + grep -q "^$monitor$" available_monitors + grep -q . "$monitor_dir"/desc + + for nested_dir in "$monitor_dir"/*; do + [ -d "$nested_dir" ] || continue + nested=$(basename "$nested_dir") + + grep -q "^$monitor:$nested$" available_monitors + grep -q . "$nested_dir"/desc + done +done diff --git a/tools/testing/selftests/verification/test.d/rv_wwnr_printk.tc b/tools/testing/selftests/verification/test.d/rv_wwnr_printk.tc new file mode 100644 index 000000000..5a59432b1 --- /dev/null +++ b/tools/testing/selftests/verification/test.d/rv_wwnr_printk.tc @@ -0,0 +1,30 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# description: Test wwnr monitor with printk reactor +# requires: available_reactors wwnr:monitor printk:reactor stress-ng:program + +load() { # returns true if there was a reaction + local lines_before num + num=$((($(nproc) + 1) / 2)) + lines_before=$(dmesg | wc -l) + stress-ng --cpu-sched "$num" --timer "$num" -t 5 -q + dmesg | tail -n $((lines_before + 1)) | grep -q "rv: monitor wwnr does not allow event" +} + +echo 1 > monitors/wwnr/enable +echo printk > monitors/wwnr/reactors + +load + +echo 0 > monitoring_on +! load +echo 1 > monitoring_on + +load + +echo 0 > reacting_on +! load +echo 1 > reacting_on + +echo nop > monitors/wwnr/reactors +echo 0 > monitors/wwnr/enable diff --git a/tools/testing/selftests/verification/verificationtest-ktap b/tools/testing/selftests/verification/verificationtest-ktap new file mode 100755 index 000000000..18f7fe324 --- /dev/null +++ b/tools/testing/selftests/verification/verificationtest-ktap @@ -0,0 +1,8 @@ +#!/bin/sh -e +# SPDX-License-Identifier: GPL-2.0-only +# +# ftracetest-ktap: Wrapper to integrate ftracetest with the kselftest runner +# +# Copyright (C) Arm Ltd., 2023 + +../ftrace/ftracetest -K -v --rv ../verification -- cgit v1.3.1