linux-stable.git/tools/testing/selftests/cgroup, branch linux-6.17.y

selftests: cgroup: Make test_pids backwards compatible

2025-10-15T10:03:17+00:00

[ Upstream commit 3b0dec689a6301845761681b852f9538cb75a1d2 ]

The predicates in test expect event counting from 73e75e6fc352b
("cgroup/pids: Separate semantics of pids.events related to pids.max")
and the test would fail on older kernels. We want to have one version of
tests for all, so detect the feature and skip the test on old kernels.
(The test could even switch to check v1 semantics based on the flag but
keep it simple for now.)

Fixes: 9f34c566027b6 ("selftests: cgroup: Add basic tests for pids controller")
Signed-off-by: Michal Koutný 
Tested-by: Sebastian Chlad 
Signed-off-by: Tejun Heo 
Signed-off-by: Sasha Levin

selftests/cgroup: fix cpu.max tests

2025-07-17T18:12:19+00:00

Current cpu.max tests (both the normal one and the nested one) are broken.

They setup cpu.max with 1000 us quota and the default period (100,000 us).
A cpu hog is run for a duration of 1s as per wall clock time. This corresponds
to 10 periods, hence an expected usage of 10,000 us. We want the measured
usage (as per cpu.stat) to be close to 10,000 us.

Previously, this approximate equality test was done by
`!values_close(usage_usec, expected_usage_usec, 95)`: if the absolute
difference between usage_usec and expected_usage_usec is greater than 95% of
their sum, then we pass. And expected_usage_usec was set to 1,000,000 us.
Mathematically, this translates to the following being true for pass:

	|usage - expected_usage| > (usage + expected_usage)*0.95

	If usage > expected_usage:
		usage - expected_usage > (usage + expected_usage)*0.95
		0.05*usage > 1.95*expected_usage
		usage > 39*expected_usage = 39s

	If usage < expected_usage:
		expected_usage - usage > (usage + expected_usage)*0.95
		0.05*expected_usage > 1.95*usage
		usage < 0.0256*expected_usage = 25,600 us

Combined,

	Pass if usage < 25,600 us or > 39 s,

which makes no sense given that all we need is for usage_usec to be close to
10,000 us.

Fix this by explicitly calcuating the expected usage duration based on the
configured quota, default period, and the duration, and compare usage_usec
and expected_usage_usec using values_close() with a 10% error margin.

Also, use snprintf to get the quota string to write to cpu.max instead of
hardcoding the quota, ensuring a single source of truth.

Remove the check comparing user_usec and expected_usage_usec, since on running
this test modified with printfs, it's seen that user_usec and usage_usec can
regularly exceed the theoretical expected_usage_usec:

	$ sudo ./test_cpu
	user: 10485, usage: 10485, expected: 10000
	ok 1 test_cpucg_max
	user: 11127, usage: 11127, expected: 10000
	ok 2 test_cpucg_max_nested
	$ sudo ./test_cpu
	user: 10286, usage: 10286, expected: 10000
	ok 1 test_cpucg_max
	user: 10404, usage: 11271, expected: 10000
	ok 2 test_cpucg_max_nested

Hence, a values_close() check of usage_usec and expected_usage_usec is
sufficient.

Fixes: a79906570f9646ae17 ("cgroup: Add test_cpucg_max_nested() testcase")
Fixes: 889ab8113ef1386c57 ("cgroup: Add test_cpucg_max() testcase")
Acked-by: Michal Koutný 
Signed-off-by: Shashank Balaji 
Signed-off-by: Tejun Heo

selftests: cgroup: Fix missing newline in test_zswap_writeback_one

2025-07-12T17:35:30+00:00

Fixes malformed test output due to missing newline

Signed-off-by: Sebastian Chlad 
Signed-off-by: Tejun Heo

selftests: cgroup: Allow longer timeout for kmem_dead_cgroups cleanup

2025-07-12T17:34:49+00:00

The test_kmem_dead_cgroups test currently assumes that RCU and
memory reclaim will complete within 5 seconds. In some environments
this timeout may be insufficient, leading to spurious test failures.

This patch introduces max_time set to 20 which is then used in the
test. After 5th sec the debug message is printed to indicate the
cleanup is still ongoing.

In the system under test with 16 CPUs the original test was failing
most of the time and the cleanup time took usually approx. 6sec.
Further tests were conducted with and without do_rcu_barrier and the
results (respectively) are as follow:
quantiles 0  0.25  0.5  0.75  1
          1    2    3    8    20 (mean = 4.7667)
          3    5    8    8    20 (mean = 7.6667)

Acked-by: Michal Koutny 
Signed-off-by: Sebastian Chlad 
Signed-off-by: Tejun Heo

selftests: cgroup: Fix compilation on pre-cgroupns kernels

2025-06-17T18:13:25+00:00

The test would be skipped because of nsdelegate, so the defined value is
not used (0 is always acceptable).

Signed-off-by: Michal Koutný 
Signed-off-by: Tejun Heo

selftests: cgroup: Optionally set up v1 environment

2025-06-17T18:13:16+00:00

Use the missing mount of the unifier hierarchy as a hint of legacy
system and prepare our own named v1 hierarchy for tests.

The code is only in test_core.c and not cgroup_util.c because other
selftests are related to controllers which will be exposed on v2
hierarchy but named hierarchies are only v1 thing.

Signed-off-by: Michal Koutný 
Signed-off-by: Tejun Heo

selftests: cgroup: Add support for named v1 hierarchies in test_core

2025-06-17T18:13:09+00:00

This comes useful when using selftests from mainline on older
kernels/setups that still rely on cgroup v1.
The core tests that rely on v2 specific features are skipped, the
remaining ones are adjusted to work with a v1 hierarchy.

The expected output on v1 system:
	ok 1 # SKIP test_cgcore_internal_process_constraint
	ok 2 # SKIP test_cgcore_top_down_constraint_enable
	ok 3 # SKIP test_cgcore_top_down_constraint_disable
	ok 4 # SKIP test_cgcore_no_internal_process_constraint_on_threads
	ok 5 # SKIP test_cgcore_parent_becomes_threaded
	ok 6 # SKIP test_cgcore_invalid_domain
	ok 7 # SKIP test_cgcore_populated
	ok 8 test_cgcore_proc_migration
	ok 9 test_cgcore_thread_migration
	ok 10 test_cgcore_destroy
	ok 11 test_cgcore_lesser_euid_open
	ok 12 # SKIP test_cgcore_lesser_ns_open

Signed-off-by: Michal Koutný 
Signed-off-by: Tejun Heo

selftests: cgroup_util: Add helpers for testing named v1 hierarchies

2025-06-17T18:13:01+00:00

Non-functional change, the control variable will be wired in a separate
commit.

Signed-off-by: Michal Koutný 
Signed-off-by: Tejun Heo

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2025-06-02T19:24:58+00:00

Pull more kvm updates from Paolo Bonzini:
  Generic:

   - Clean up locking of all vCPUs for a VM by using the *_nest_lock()
     family of functions, and move duplicated code to virt/kvm/. kernel/
     patches acked by Peter Zijlstra

   - Add MGLRU support to the access tracking perf test

  ARM fixes:

   - Make the irqbypass hooks resilient to changes in the GSI<->MSI
     routing, avoiding behind stale vLPI mappings being left behind. The
     fix is to resolve the VGIC IRQ using the host IRQ (which is stable)
     and nuking the vLPI mapping upon a routing change

   - Close another VGIC race where vCPU creation races with VGIC
     creation, leading to in-flight vCPUs entering the kernel w/o
     private IRQs allocated

   - Fix a build issue triggered by the recently added workaround for
     Ampere's AC04_CPU_23 erratum

   - Correctly sign-extend the VA when emulating a TLBI instruction
     potentially targeting a VNCR mapping

   - Avoid dereferencing a NULL pointer in the VGIC debug code, which
     can happen if the device doesn't have any mapping yet

  s390:

   - Fix interaction between some filesystems and Secure Execution

   - Some cleanups and refactorings, preparing for an upcoming big
     series

  x86:

   - Wait for target vCPU to ack KVM_REQ_UPDATE_PROTECTED_GUEST_STATE
     to fix a race between AP destroy and VMRUN

   - Decrypt and dump the VMSA in dump_vmcb() if debugging enabled for
     the VM

   - Refine and harden handling of spurious faults

   - Add support for ALLOWED_SEV_FEATURES

   - Add #VMGEXIT to the set of handlers special cased for
     CONFIG_RETPOLINE=y

   - Treat DEBUGCTL[5:2] as reserved to pave the way for virtualizing
     features that utilize those bits

   - Don't account temporary allocations in sev_send_update_data()

   - Add support for KVM_CAP_X86_BUS_LOCK_EXIT on SVM, via Bus Lock
     Threshold

   - Unify virtualization of IBRS on nested VM-Exit, and cross-vCPU
     IBPB, between SVM and VMX

   - Advertise support to userspace for WRMSRNS and PREFETCHI

   - Rescan I/O APIC routes after handling EOI that needed to be
     intercepted due to the old/previous routing, but not the
     new/current routing

   - Add a module param to control and enumerate support for device
     posted interrupts

   - Fix a potential overflow with nested virt on Intel systems running
     32-bit kernels

   - Flush shadow VMCSes on emergency reboot

   - Add support for SNP to the various SEV selftests

   - Add a selftest to verify fastops instructions via forced emulation

   - Refine and optimize KVM's software processing of the posted
     interrupt bitmap, and share the harvesting code between KVM and the
     kernel's Posted MSI handler"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (93 commits)
  rtmutex_api: provide correct extern functions
  KVM: arm64: vgic-debug: Avoid dereferencing NULL ITE pointer
  KVM: arm64: vgic-init: Plug vCPU vs. VGIC creation race
  KVM: arm64: Unmap vLPIs affected by changes to GSI routing information
  KVM: arm64: Resolve vLPI by host IRQ in vgic_v4_unset_forwarding()
  KVM: arm64: Protect vLPI translation with vgic_irq::irq_lock
  KVM: arm64: Use lock guard in vgic_v4_set_forwarding()
  KVM: arm64: Mask out non-VA bits from TLBI VA* on VNCR invalidation
  arm64: sysreg: Drag linux/kconfig.h to work around vdso build issue
  KVM: s390: Simplify and move pv code
  KVM: s390: Refactor and split some gmap helpers
  KVM: s390: Remove unneeded srcu lock
  s390: Remove unneeded includes
  s390/uv: Improve splitting of large folios that cannot be split while dirty
  s390/uv: Always return 0 from s390_wiggle_split_folio() if successful
  s390/uv: Don't return 0 from make_hva_secure() if the operation was not successful
  rust: add helper for mutex_trylock
  RISC-V: KVM: use kvm_trylock_all_vcpus when locking all vCPUs
  KVM: arm64: use kvm_trylock_all_vcpus when locking all vCPUs
  x86: KVM: SVM: use kvm_lock_all_vcpus instead of a custom implementation
  ...

cgroup: selftests: Add API to find root of specific controller

2025-05-16T18:45:15+00:00

Add an API in the cgroups library to find the root of a specific
controller.  KVM selftests will use the API to find the memory controller.

Search for the controller on both v1 and v2 mounts, as KVM selftests'
usage will be completely oblivious of v1 versus v2.

Signed-off-by: James Houghton 
Link: https://lore.kernel.org/r/20250508184649.2576210-6-jthoughton@google.com
Signed-off-by: Sean Christopherson