Tejun Heo
842b597ee0
cgroup: implement cgroup.populated for the default hierarchy
...
cgroup users often need a way to determine when a cgroup's
subhierarchy becomes empty so that it can be cleaned up. cgroup
currently provides release_agent for it; unfortunately, this mechanism
is riddled with issues.
* It delivers events by forking and execing a userland binary
specified as the release_agent. This is a long deprecated method of
notification delivery. It's extremely heavy, slow and cumbersome to
integrate with larger infrastructure.
* There is single monitoring point at the root. There's no way to
delegate management of a subtree.
* The event isn't recursive. It triggers when a cgroup doesn't have
any tasks or child cgroups. Events for internal nodes trigger only
after all children are removed. This again makes it impossible to
delegate management of a subtree.
* Events are filtered from the kernel side. "notify_on_release" file
is used to subscribe to or suppress release event. This is
unnecessarily complicated and probably done this way because event
delivery itself was expensive.
This patch implements interface file "cgroup.populated" which can be
used to monitor whether the cgroup's subhierarchy has tasks in it or
not. Its value is 0 if there is no task in the cgroup and its
descendants; otherwise, 1, and kernfs_notify() notificaiton is
triggers when the value changes, which can be monitored through poll
and [di]notify.
This is a lot ligther and simpler and trivially allows delegating
management of subhierarchy - subhierarchy monitoring can block further
propgation simply by putting itself or another process in the root of
the subhierarchy and monitor events that it's interested in from there
without interfering with monitoring higher in the tree.
v2: Patch description updated as per Serge.
v3: "cgroup.subtree_populated" renamed to "cgroup.populated". The
subtree_ prefix was a bit confusing because
"cgroup.subtree_control" uses it to denote the tree rooted at the
cgroup sans the cgroup itself while the populated state includes
the cgroup itself.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Lennart Poettering <lennart@poettering.net>
2014-04-25 18:28:02 -04:00
..
debug
mm: per-thread vma caching
2014-04-07 16:35:53 -07:00
events
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
2014-04-05 13:20:43 -07:00
gcov
irq
genirq: Export symbol no_action()
2014-03-22 11:33:09 +01:00
locking
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-16 16:35:18 -07:00
power
kernel: use macros from compiler.h instead of __attribute__((...))
2014-04-07 16:36:11 -07:00
printk
printk: fix one circular lockdep warning about console_lock
2014-04-03 16:21:08 -07:00
rcu
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 11:21:19 -07:00
sched
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-19 10:40:51 -07:00
time
tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz()
2014-04-15 20:26:58 +02:00
trace
This contains two fixes.
2014-04-18 10:16:43 -07:00
.gitignore
Ignore generated file kernel/x509_certificate_list
2013-12-10 18:21:34 +00:00
acct.c
async.c
audit.c
Merge git://git.infradead.org/users/eparis/audit
2014-04-12 12:38:53 -07:00
audit.h
audit: Use struct net not pid_t to remember the network namespce to reply in
2014-03-20 10:10:53 -04:00
audit_tree.c
inotify: Fix reporting of cookies for inotify events
2014-02-18 11:17:17 +01:00
audit_watch.c
inotify: Fix reporting of cookies for inotify events
2014-02-18 11:17:17 +01:00
auditfilter.c
Merge git://git.infradead.org/users/eparis/audit
2014-04-12 12:38:53 -07:00
auditsc.c
Merge git://git.infradead.org/users/eparis/audit
2014-04-12 12:38:53 -07:00
backtracetest.c
bounds.c
mm: do not allocate page->ptl dynamically, if spinlock_t fits to long
2013-12-20 12:25:45 -08:00
capability.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2014-04-03 09:26:18 -07:00
cgroup.c
cgroup: implement cgroup.populated for the default hierarchy
2014-04-25 18:28:02 -04:00
cgroup_freezer.c
cgroup: drop const from @buffer of cftype->write_string()
2014-03-19 10:23:54 -04:00
compat.c
Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-02 12:51:41 -07:00
configs.c
context_tracking.c
context_tracking: Wrap static key check into more intuitive function name
2013-12-02 20:43:14 +01:00
cpu.c
CPU hotplug: Provide lockless versions of callback registration functions
2014-03-20 13:43:40 +01:00
cpu_pm.c
cpuset.c
Merge branch 'akpm' (incoming from Andrew)
2014-04-03 16:22:16 -07:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
wait: WSTOPPED|WCONTINUED doesn't work if a zombie leader is traced by another process
2014-04-07 16:36:06 -07:00
extable.c
asmlinkage: Make main_extable_sort_needed visible
2014-02-13 18:13:22 -08:00
fork.c
kernel: use macros from compiler.h instead of __attribute__((...))
2014-04-07 16:36:11 -07:00
freezer.c
libata, freezer: avoid block device removal while system is frozen
2013-12-19 13:50:32 -05:00
futex.c
futex: update documentation for ordering guarantees
2014-04-12 17:57:51 -07:00
futex_compat.c
compat: Get rid of (get|put)_compat_time(val|spec)
2014-02-02 14:09:12 -08:00
groups.c
kernel/groups.c: remove return value of set_groups
2014-04-03 16:21:05 -07:00
hrtimer.c
timer: Remove code redundancy while calling get_nohz_timer_target()
2014-03-20 12:35:46 +01:00
hung_task.c
kernel: audit/fix non-modular users of module_init in core code
2014-04-03 16:21:07 -07:00
irq_work.c
perf/x86: Warn to early_printk() in case irq_work is too slow
2014-02-21 21:49:07 +01:00
itimer.c
jump_label.c
kallsyms.c
kernel: use macros from compiler.h instead of __attribute__((...))
2014-04-07 16:36:11 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kernel: use macros from compiler.h instead of __attribute__((...))
2014-04-07 16:36:11 -07:00
kmod.c
execve: use 'struct filename *' for executable name passing
2014-02-05 12:54:53 -08:00
kprobes.c
ksysfs.c
kobject: Make support for uevent_helper optional.
2014-04-25 12:00:49 -07:00
kthread.c
kthread: ensure locality of task_struct allocations
2014-04-03 16:20:49 -07:00
latencytop.c
Makefile
Merge branch 'x86-asmlinkage-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-03-31 14:13:25 -07:00
module-internal.h
module.c
modules: use raw_cpu_write for initialization of per cpu refcount.
2014-04-07 16:36:14 -07:00
module_signing.c
notifier.c
notifier: Substitute rcu_access_pointer() for rcu_dereference_raw()
2014-02-26 06:35:13 -08:00
nsproxy.c
padata.c
padata: Fix wrong usage of rcu_dereference()
2013-12-05 21:28:42 +08:00
panic.c
kernel/panic.c: display reason at end + pr_emerg
2014-04-07 16:36:08 -07:00
params.c
params: improve standard definitions
2013-12-04 14:09:46 +10:30
pid.c
pid_namespace.c
pid_namespace: pidns_get() should check task_active_pid_ns() != NULL
2014-04-02 16:20:21 -07:00
posix-cpu-timers.c
posix-timers: Convert abuses of BUG_ON to WARN_ON
2013-12-09 16:56:29 +01:00
posix-timers.c
profile.c
CPU hotplug notifiers registration fixes for 3.15-rc1
2014-04-07 14:55:46 -07:00
ptrace.c
kernel/compat: convert to COMPAT_SYSCALL_DEFINE
2014-03-06 15:35:10 +01:00
range.c
reboot.c
kexec: migrate to reboot cpu
2013-12-18 19:04:50 -08:00
relay.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2014-04-12 14:49:50 -07:00
res_counter.c
res_counter: remove interface for locked charging and uncharging
2014-04-07 16:35:54 -07:00
resource.c
kernel/resource.c: make reallocate_resource() static
2014-04-03 16:21:07 -07:00
seccomp.c
seccomp: fix memory leak on filter attach
2014-04-16 15:25:53 -04:00
signal.c
kernel: use macros from compiler.h instead of __attribute__((...))
2014-04-07 16:36:11 -07:00
smp.c
smp: Rename __smp_call_function_single() to smp_call_function_single_async()
2014-02-24 14:47:15 -08:00
smpboot.c
smpboot.h
softirq.c
softirq: Add linux/irq.h to make it compile again
2014-03-19 11:28:14 +01:00
stacktrace.c
stop_machine.c
stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus()
2014-03-11 11:33:47 +01:00
sys.c
mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLE
2014-04-07 16:35:52 -07:00
sys_ni.c
fs, kernel: permit disabling the uselib syscall
2014-04-03 16:21:05 -07:00
sysctl.c
kobject: Make support for uevent_helper optional.
2014-04-25 12:00:49 -07:00
sysctl_binary.c
system_certificates.S
KEYS: correct alignment of system_certificate_list content in assembly file
2013-12-10 18:25:28 +00:00
system_keyring.c
KEYS: correct alignment of system_certificate_list content in assembly file
2013-12-10 18:25:28 +00:00
task_work.c
taskstats.c
test_kprobes.c
time.c
timeconst.bc
timer.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-01 11:00:07 -07:00
torture.c
rcutorture: Gracefully handle NULL cleanup hooks
2014-02-23 09:04:39 -08:00
tracepoint.c
This includes the final patch to clean up and fix the issue with the
2014-04-12 13:06:10 -07:00
tsacct.c
uid16.c
up.c
smp: Rename __smp_call_function_single() to smp_call_function_single_async()
2014-02-24 14:47:15 -08:00
user-return-notifier.c
user.c
kernel: audit/fix non-modular users of module_init in core code
2014-04-03 16:21:07 -07:00
user_namespace.c
user namespace: fix incorrect memory barriers
2014-04-14 16:03:02 -07:00
utsname.c
utsname_sysctl.c
watchdog.c
kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()
2014-04-18 16:40:08 -07:00
workqueue.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2014-04-01 11:00:07 -07:00
workqueue_internal.h