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author | Christian Brauner <christian.brauner@ubuntu.com> | 2020-02-05 14:26:22 +0100 |
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committer | Tejun Heo <tj@kernel.org> | 2020-02-12 17:57:51 -0500 |
commit | ef2c41cf38a7559bbf91af42d5b6a4429db8fc68 (patch) | |
tree | ad5801b2782c5268dc0ad1b6f0f591b1da582eee /tools/testing/selftests/clone3 | |
parent | f3553220d4cc458d69f7da6e71a3a6097778bd28 (diff) |
clone3: allow spawning processes into cgroups
This adds support for creating a process in a different cgroup than its
parent. Callers can limit and account processes and threads right from
the moment they are spawned:
- A service manager can directly spawn new services into dedicated
cgroups.
- A process can be directly created in a frozen cgroup and will be
frozen as well.
- The initial accounting jitter experienced by process supervisors and
daemons is eliminated with this.
- Threaded applications or even thread implementations can choose to
create a specific cgroup layout where each thread is spawned
directly into a dedicated cgroup.
This feature is limited to the unified hierarchy. Callers need to pass
a directory file descriptor for the target cgroup. The caller can
choose to pass an O_PATH file descriptor. All usual migration
restrictions apply, i.e. there can be no processes in inner nodes. In
general, creating a process directly in a target cgroup adheres to all
migration restrictions.
One of the biggest advantages of this feature is that CLONE_INTO_GROUP does
not need to grab the write side of the cgroup cgroup_threadgroup_rwsem.
This global lock makes moving tasks/threads around super expensive. With
clone3() this lock is avoided.
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'tools/testing/selftests/clone3')
0 files changed, 0 insertions, 0 deletions