Loading Documentation/cgroup-v2.txt +41 −0 Original line number Diff line number Diff line Loading @@ -47,6 +47,8 @@ CONTENTS 5-3. IO 5-3-1. IO Interface Files 5-3-2. Writeback 5-4. PID 5-4-1. PID Interface Files 6. Namespace 6-1. Basics 6-2. The Root and Views Loading Loading @@ -1119,6 +1121,45 @@ writeback as follows. vm.dirty[_background]_ratio. 5-4. PID The process number controller is used to allow a cgroup to stop any new tasks from being fork()'d or clone()'d after a specified limit is reached. The number of tasks in a cgroup can be exhausted in ways which other controllers cannot prevent, thus warranting its own controller. For example, a fork bomb is likely to exhaust the number of tasks before hitting memory restrictions. Note that PIDs used in this controller refer to TIDs, process IDs as used by the kernel. 5-4-1. PID Interface Files pids.max A read-write single value file which exists on non-root cgroups. The default is "max". Hard limit of number of processes. pids.current A read-only single value file which exists on all cgroups. The number of processes currently in the cgroup and its descendants. Organisational operations are not blocked by cgroup policies, so it is possible to have pids.current > pids.max. This can be done by either setting the limit to be smaller than pids.current, or attaching enough processes to the cgroup such that pids.current is larger than pids.max. However, it is not possible to violate a cgroup PID policy through fork() or clone(). These will return -EAGAIN if the creation of a new process would cause a cgroup policy to be violated. 6. Namespace 6-1. Basics Loading Loading
Documentation/cgroup-v2.txt +41 −0 Original line number Diff line number Diff line Loading @@ -47,6 +47,8 @@ CONTENTS 5-3. IO 5-3-1. IO Interface Files 5-3-2. Writeback 5-4. PID 5-4-1. PID Interface Files 6. Namespace 6-1. Basics 6-2. The Root and Views Loading Loading @@ -1119,6 +1121,45 @@ writeback as follows. vm.dirty[_background]_ratio. 5-4. PID The process number controller is used to allow a cgroup to stop any new tasks from being fork()'d or clone()'d after a specified limit is reached. The number of tasks in a cgroup can be exhausted in ways which other controllers cannot prevent, thus warranting its own controller. For example, a fork bomb is likely to exhaust the number of tasks before hitting memory restrictions. Note that PIDs used in this controller refer to TIDs, process IDs as used by the kernel. 5-4-1. PID Interface Files pids.max A read-write single value file which exists on non-root cgroups. The default is "max". Hard limit of number of processes. pids.current A read-only single value file which exists on all cgroups. The number of processes currently in the cgroup and its descendants. Organisational operations are not blocked by cgroup policies, so it is possible to have pids.current > pids.max. This can be done by either setting the limit to be smaller than pids.current, or attaching enough processes to the cgroup such that pids.current is larger than pids.max. However, it is not possible to violate a cgroup PID policy through fork() or clone(). These will return -EAGAIN if the creation of a new process would cause a cgroup policy to be violated. 6. Namespace 6-1. Basics Loading
Hans Ragas <hansr@fb.com> Signed-off-by: