This patchset implements freezer for cgroup v2. It provides similar functionality as v1 freezer, but the interface conforms to the cgroup v2 interface design principles, and it provides a better user experience: tasks can be killed, ptrace works, there is no separate controller, which has to be enabled, etc. Patches (1) and (2) are some preparational work, patch (3) contains the implementation, patch (4) is a small cgroup kselftest fix, patch (5) covers freezer adds 6 new kselftests to cover the freezer functionality. Roman Gushchin (5): cgroup: rename freezer.c into legacy_freezer.c cgroup: implement __cgroup_task_count() helper cgroup: cgroup v2 freezer kselftests: cgroup: don't fail on cg_kill_all() error in cg_destroy() kselftests: cgroup: add freezer controller self-tests include/linux/cgroup-defs.h | 33 + include/linux/cgroup.h | 42 ++ include/linux/sched.h | 5 +- include/linux/sched/jobctl.h | 5 +- kernel/cgroup/Makefile | 4 +- kernel/cgroup/cgroup-internal.h | 1 + kernel/cgroup/cgroup-v1.c | 16 - kernel/cgroup/cgroup.c | 132 +++- kernel/cgroup/freezer.c | 590 +++++---------- kernel/cgroup/legacy_freezer.c | 481 ++++++++++++ kernel/ptrace.c | 6 + kernel/signal.c | 51 +- tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/cgroup_util.c | 85 ++- tools/testing/selftests/cgroup/cgroup_util.h | 7 + tools/testing/selftests/cgroup/test_freezer.c | 685 ++++++++++++++++++ 17 files changed, 1695 insertions(+), 451 deletions(-) create mode 100644 kernel/cgroup/legacy_freezer.c create mode 100644 tools/testing/selftests/cgroup/test_freezer.c -- 2.17.2