It's possible to run these tests on platforms that think they have a
hotpluggable CPU1, but for whatever reason, CPU1 is not online and can't be
brought online:
# irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:210
Expected remove_cpu(1) == 0, but
remove_cpu(1) == 1 (0x1)
CPU1: failed to boot: -38
# irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:214
Expected add_cpu(1) == 0, but
add_cpu(1) == -38 (0xffffffffffffffda)
Check that CPU1 is actually online before trying to run the test.
Fixes: 66067c3c8a ("genirq: Add kunit tests for depth counts")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20250822190140.2154646-7-briannorris@chromium.org
Not all platforms use the generic IRQ migration code, even if they select
GENERIC_IRQ_MIGRATION. (See, for example, powerpc / pseries_cpu_disable().)
If such platforms don't perform managed shutdown the same way, the interrupt
may not actually shut down, and these tests fail:
[ 4.357022][ T101] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:211
[ 4.357022][ T101] Expected irqd_is_activated(data) to be false, but is true
[ 4.358128][ T101] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:212
[ 4.358128][ T101] Expected irqd_is_started(data) to be false, but is true
[ 4.375558][ T101] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:216
[ 4.375558][ T101] Expected irqd_is_activated(data) to be false, but is true
[ 4.376088][ T101] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:217
[ 4.376088][ T101] Expected irqd_is_started(data) to be false, but is true
[ 4.377851][ T1] # irq_cpuhotplug_test: pass:0 fail:1 skip:0 total:1
[ 4.377901][ T1] not ok 4 irq_cpuhotplug_test
[ 4.378073][ T1] # irq_test_cases: pass:3 fail:1 skip:0 total:4
Rather than test that PowerPC performs migration the same way as the
unterrupt core, just drop the state checks. The point of the test was to
ensure that the code kept |depth| balanced, which still can be tested for.
Fixes: 66067c3c8a ("genirq: Add kunit tests for depth counts")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20250822190140.2154646-6-briannorris@chromium.org
Requesting an interrupt is part of the basic test setup. If it fails, most
of the subsequent tests are likely to fail, and the output gets noisy.
Use "assert" to fail early.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20250822190140.2154646-4-briannorris@chromium.org
A few things need to be repeated in tests. Factor out the creation of fake
interrupts.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20250822190140.2154646-3-briannorris@chromium.org
The new irq KUnit tests fail on some architectures (notably PowerPC and
32-bit ARM), as the request_irq() call fails due to the ARCH_IRQ_INIT_FLAGS
containing IRQ_NOREQUEST, yielding the following errors:
[10:17:45] # irq_free_disabled_test: EXPECTATION FAILED at kernel/irq/irq_test.c:88
[10:17:45] Expected ret == 0, but
[10:17:45] ret == -22 (0xffffffffffffffea)
[10:17:45] # irq_free_disabled_test: EXPECTATION FAILED at kernel/irq/irq_test.c:90
[10:17:45] Expected desc->depth == 0, but
[10:17:45] desc->depth == 1 (0x1)
[10:17:45] # irq_free_disabled_test: EXPECTATION FAILED at kernel/irq/irq_test.c:93
[10:17:45] Expected desc->depth == 1, but
[10:17:45] desc->depth == 2 (0x2)
By clearing IRQ_NOREQUEST from the interrupt descriptor, these tests now
pass on ARM and PowerPC.
Fixes: 66067c3c8a ("genirq: Add kunit tests for depth counts")
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/all/20250816094528.3560222-2-davidgow@google.com
irq_shutdown_and_deactivate() is normally called with the descriptor lock
held, and interrupts disabled. Nested a few levels down, it grabs the
global irq_resend_lock. Lockdep rightfully complains when interrupts are
not disabled:
CPU0 CPU1
---- ----
lock(irq_resend_lock);
local_irq_disable();
lock(&irq_desc_lock_class);
lock(irq_resend_lock);
<Interrupt>
lock(&irq_desc_lock_class);
...
_raw_spin_lock+0x2b/0x40
clear_irq_resend+0x14/0x70
irq_shutdown_and_deactivate+0x29/0x80
irq_shutdown_depth_test+0x1ce/0x600
kunit_try_run_case+0x90/0x120
Grab the descriptor lock and disable interrupts, to resolve the
problem.
Fixes: 66067c3c8a ("genirq: Add kunit tests for depth counts")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/aJJONEIoIiTSDMqc@google.com
Closes: https://lore.kernel.org/lkml/31a761e4-8f81-40cf-aaf5-d220ba11911c@roeck-us.net/
There have been a few bugs and/or misunderstandings about the reference
counting, and startup/shutdown behaviors in the IRQ core and related CPU
hotplug code. These 4 test cases try to capture a few interesting cases.
* irq_disable_depth_test: basic request/disable/enable sequence
* irq_free_disabled_test: request/disable/free/re-request sequence -
this catches errors on previous revisions of my work
* irq_cpuhotplug_test: exercises managed-affinity IRQ + CPU hotplug.
This captures a problematic test case which was fixed recently.
This test requires CONFIG_SMP and a hotpluggable CPU#1.
* irq_shutdown_depth_test: exercises similar behavior from
irq_cpuhotplug_test, but directly using irq_*() APIs instead of going
through CPU hotplug. This still requires CONFIG_SMP, because
managed-affinity is stubbed out (and not all APIs are even present)
without it.
Note the use of 'imply SMP': ARCH=um doesn't support SMP, and kunit is
often exercised there. Thus, 'imply' will force SMP on where possible
(such as ARCH=x86_64), but leave it off where it's not.
Behavior on various SMP and ARCH configurations:
$ tools/testing/kunit/kunit.py run 'irq_test_cases*' --arch x86_64 --qemu_args '-smp 2'
[...]
[11:12:24] Testing complete. Ran 4 tests: passed: 4
$ tools/testing/kunit/kunit.py run 'irq_test_cases*' --arch x86_64
[...]
[11:13:27] [SKIPPED] irq_cpuhotplug_test
[11:13:27] ================= [PASSED] irq_test_cases ==================
[11:13:27] ============================================================
[11:13:27] Testing complete. Ran 4 tests: passed: 3, skipped: 1
# default: ARCH=um
$ tools/testing/kunit/kunit.py run 'irq_test_cases*'
[11:14:26] [SKIPPED] irq_shutdown_depth_test
[11:14:26] [SKIPPED] irq_cpuhotplug_test
[11:14:26] ================= [PASSED] irq_test_cases ==================
[11:14:26] ============================================================
[11:14:26] Testing complete. Ran 4 tests: passed: 2, skipped: 2
Without commit 788019eb55 ("genirq: Retain disable depth for managed
interrupts across CPU hotplug"), this fails as follows:
[11:18:55] =============== irq_test_cases (4 subtests) ================
[11:18:55] [PASSED] irq_disable_depth_test
[11:18:55] [PASSED] irq_free_disabled_test
[11:18:55] # irq_shutdown_depth_test: EXPECTATION FAILED at kernel/irq/irq_test.c:147
[11:18:55] Expected desc->depth == 1, but
[11:18:55] desc->depth == 0 (0x0)
[11:18:55] ------------[ cut here ]------------
[11:18:55] Unbalanced enable for IRQ 26
[11:18:55] WARNING: CPU: 1 PID: 36 at kernel/irq/manage.c:792 __enable_irq+0x36/0x60
...
[11:18:55] [FAILED] irq_shutdown_depth_test
[11:18:55] #1
[11:18:55] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:202
[11:18:55] Expected irqd_is_activated(data) to be false, but is true
[11:18:55] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:203
[11:18:55] Expected irqd_is_started(data) to be false, but is true
[11:18:55] # irq_cpuhotplug_test: EXPECTATION FAILED at kernel/irq/irq_test.c:204
[11:18:55] Expected desc->depth == 1, but
[11:18:55] desc->depth == 0 (0x0)
[11:18:55] ------------[ cut here ]------------
[11:18:55] Unbalanced enable for IRQ 27
[11:18:55] WARNING: CPU: 0 PID: 38 at kernel/irq/manage.c:792 __enable_irq+0x36/0x60
...
[11:18:55] [FAILED] irq_cpuhotplug_test
[11:18:55] # module: irq_test
[11:18:55] # irq_test_cases: pass:2 fail:2 skip:0 total:4
[11:18:55] # Totals: pass:2 fail:2 skip:0 total:4
[11:18:55] ================= [FAILED] irq_test_cases ==================
[11:18:55] ============================================================
[11:18:55] Testing complete. Ran 4 tests: passed: 2, failed: 2
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250522210837.4135244-1-briannorris@chromium.org
Brian Norris
David Gow