kernel/linux.git/tools/testing/selftests/cgroup/test_core.c, branch v7.1

selftests/cgroup: Don't require synchronous populated update on task exit

2026-03-24T20:21:57+00:00

test_cgcore_populated (test_core) and test_cgkill_{simple,tree,forkbomb} (test_kill) check cgroup.events "populated 0" immediately after reaping child tasks with waitpid(). This used to work because cgroup_task_exit() in do_exit() unlinked tasks from css_sets before exit_notify() woke up waitpid(). d245698d727a ("cgroup: Defer task cgroup unlink until after the task is done switching out") moved the unlink to cgroup_task_dead() in finish_task_switch(), which runs after exit_notify(). The populated counter is now decremented after the parent's waitpid() can return, so there is no longer a synchronous ordering guarantee. On PREEMPT_RT, where cgroup_task_dead() is further deferred through lazy irq_work, the race window is even larger. The synchronous populated transition was never part of the cgroup interface contract - it was an implementation artifact. Use cg_read_strcmp_wait() which retries for up to 1 second, matching what these tests actually need to verify: that the cgroup eventually becomes unpopulated after all tasks exit. Fixes: d245698d727a ("cgroup: Defer task cgroup unlink until after the task is done switching out") Reported-by: Sebastian Andrzej Siewior Signed-off-by: Tejun Heo Tested-by: Sebastian Andrzej Siewior Cc: Christian Brauner Cc: cgroups@vger.kernel.org

Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-12-06T22:01:20+00:00

Pull non-MM updates from Andrew Morton: - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko) fixes a build issue and does some cleanup in ib/sys_info.c - "Implement mul_u64_u64_div_u64_roundup()" (David Laight) enhances the 64-bit math code on behalf of a PWM driver and beefs up the test module for these library functions - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich) makes BPF symbol names, sizes, and line numbers available to the GDB debugger - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang) adds a sysctl which can be used to cause additional info dumping when the hung-task and lockup detectors fire - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu) adds a general base64 encoder/decoder to lib/ and migrates several users away from their private implementations - "rbree: inline rb_first() and rb_last()" (Eric Dumazet) makes TCP a little faster - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin) reworks the KEXEC Handover interfaces in preparation for Live Update Orchestrator (LUO), and possibly for other future clients - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin) increases the flexibility of KEXEC Handover. Also preparation for LUO - "Live Update Orchestrator" (Pasha Tatashin) is a major new feature targeted at cloud environments. Quoting the cover letter: This series introduces the Live Update Orchestrator, a kernel subsystem designed to facilitate live kernel updates using a kexec-based reboot. This capability is critical for cloud environments, allowing hypervisors to be updated with minimal downtime for running virtual machines. LUO achieves this by preserving the state of selected resources, such as memory, devices and their dependencies, across the kernel transition. As a key feature, this series includes support for preserving memfd file descriptors, which allows critical in-memory data, such as guest RAM or any other large memory region, to be maintained in RAM across the kexec reboot. Mike Rappaport merits a mention here, for his extensive review and testing work. - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain) moves the kexec and kdump sysfs entries from /sys/kernel/ to /sys/kernel/kexec/ and adds back-compatibility symlinks which can hopefully be removed one day - "kho: fixes for vmalloc restoration" (Mike Rapoport) fixes a BUG which was being hit during KHO restoration of vmalloc() regions * tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits) calibrate: update header inclusion Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()" vmcoreinfo: track and log recoverable hardware errors kho: fix restoring of contiguous ranges of order-0 pages kho: kho_restore_vmalloc: fix initialization of pages array MAINTAINERS: TPM DEVICE DRIVER: update the W-tag init: replace simple_strtoul with kstrtoul to improve lpj_setup KHO: fix boot failure due to kmemleak access to non-PRESENT pages Documentation/ABI: new kexec and kdump sysfs interface Documentation/ABI: mark old kexec sysfs deprecated kexec: move sysfs entries to /sys/kernel/kexec test_kho: always print restore status kho: free chunks using free_page() instead of kfree() selftests/liveupdate: add kexec test for multiple and empty sessions selftests/liveupdate: add simple kexec-based selftest for LUO selftests/liveupdate: add userspace API selftests docs: add documentation for memfd preservation via LUO mm: memfd_luo: allow preserving memfd liveupdate: luo_file: add private argument to store runtime state mm: shmem: export some functions to internal.h ...

selftests: complete kselftest include centralization

2025-11-27T22:24:31+00:00

This follow-up patch completes centralization of kselftest.h and ksefltest_harness.h includes in remaining seltests files, replacing all relative paths with a non-relative paths using shared -I include path in lib.mk Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on riscv, arm64, x86_64 and powerpc arch. [reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h] Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com Signed-off-by: Bala-Vignesh-Reddy Suggested-by: Andrew Morton Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang Cc: David Hildenbrand Cc: David S. Miller Cc: Eric Dumazet Cc: Günther Noack Cc: Jakub Kacinski Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mickael Salaun Cc: Ming Lei Cc: Paolo Abeni Cc: Shuah Khan Cc: Simon Horman Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/cgroup: conform test to KTAP format output

2025-11-14T18:12:57+00:00

Conform the layout, informational and status messages to KTAP. No functional change is intended other than the layout of output messages. Signed-off-by: Guopeng Zhang Suggested-by: Sebastian Chlad Acked-by: Michal Koutný 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

Revert "selftests/cgroup: Drop define _GNU_SOURCE"

2024-05-20T15:00:15+00:00

This reverts commit c1457d9aad5ee2feafcf85aa9a58ab50500159d2. The framework change to add D_GNU_SOURCE to KHDR_INCLUDES to Makefile, lib.mk, and kselftest_harness.h is reverted as it is causing build failures and warnings. Revert this change as this change depends on the framework change. Reported-by: Mark Brown Signed-off-by: Shuah Khan

selftests/cgroup: Drop define _GNU_SOURCE

2024-05-13T17:02:36+00:00

_GNU_SOURCE is provided by lib.mk, so it should be dropped to prevent redefinition warnings. Signed-off-by: Edward Liaw Signed-off-by: Tejun Heo