linux/init
Aleksa Sarai 49b786ea14 cgroup: implement the PIDs subsystem
Adds a new single-purpose PIDs subsystem to limit the number of
tasks that can be forked inside a cgroup. Essentially this is an
implementation of RLIMIT_NPROC that applies to a cgroup rather than a
process tree.

However, it should be noted that organisational operations (adding and
removing tasks from a PIDs hierarchy) will *not* be prevented. Rather,
the number of tasks in the hierarchy cannot exceed the limit through
forking. This is due to the fact that, in the unified hierarchy, attach
cannot fail (and it is not possible for a task to overcome its PIDs
cgroup policy limit by attaching to a child cgroup -- even if migrating
mid-fork it must be able to fork in the parent first).

PIDs are fundamentally a global resource, and it is possible to reach
PID exhaustion inside a cgroup without hitting any reasonable kmemcg
policy. Once you've hit PID exhaustion, you're only in a marginally
better state than OOM. This subsystem allows PID exhaustion inside a
cgroup to be prevented.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2015-07-14 17:29:23 -04:00
..
calibrate.c kernel: add calibration_delay_done() 2014-06-16 12:47:39 -06:00
do_mounts_initrd.c usermodehelper: split remaining calls to call_usermodehelper_fns() 2013-04-30 17:04:06 -07:00
do_mounts_md.c init: disable sparse checking of the mount.o source files 2012-05-31 17:49:27 -07:00
do_mounts_rd.c initramfs: support initramfs that is bigger than 2GiB 2014-08-08 15:57:26 -07:00
do_mounts.c init/do_mounts.c: add create_dev() failure log 2015-06-25 17:00:42 -07:00
do_mounts.h md: move lots of #include lines out of .h files and into .c 2009-03-31 14:33:13 +11:00
init_task.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
initramfs.c init/initramfs.c: resolve shadow warnings 2014-10-14 02:18:22 +02:00
Kconfig cgroup: implement the PIDs subsystem 2015-07-14 17:29:23 -04:00
main.c mm: meminit: finish initialisation of struct pages before basic setup 2015-06-30 19:44:56 -07:00
Makefile init_task: Replace CONFIG_HAVE_GENERIC_INIT_TASK 2012-05-05 13:00:46 +02:00
noinitramfs.c init: mark __user address space on string literals 2010-10-26 16:52:15 -07:00
version.c copy address of proc_ns_ops into ns_common 2014-12-04 14:34:47 -05:00