linux/include
Tejun Heo 27bd4dbb8d cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
Currently, cgroup_has_tasks() tests whether the target cgroup has any
css_set linked to it.  This works because a css_set's refcnt converges
with the number of tasks linked to it and thus there's no css_set
linked to a cgroup if it doesn't have any live tasks.

To help tracking resource usage of zombie tasks, putting the ref of
css_set will be separated from disassociating the task from the
css_set which means that a cgroup may have css_sets linked to it even
when it doesn't have any live tasks.

This patch replaces cgroup_has_tasks() with cgroup_is_populated()
which tests cgroup->nr_populated instead which locally counts the
number of populated css_sets.  Unlike cgroup_has_tasks(),
cgroup_is_populated() is recursive - if any of the descendants is
populated, the cgroup is populated too.  While this changes the
meaning of the test, all the existing users are okay with the change.

While at it, replace the open-coded ->populated_cnt test in
cgroup_events_show() with cgroup_is_populated().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
2015-10-15 16:41:50 -04:00
..
acpi Merge branch 'pm-cpufreq' 2015-09-01 15:52:35 +02:00
asm-generic dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-09-08 12:41:25 -07:00
drm Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-09-04 15:49:32 -07:00
dt-bindings Merge branch 'drivers/reset' into next/late 2015-09-09 15:42:45 -07:00
keys
kvm
linux cgroup: replace cgroup_has_tasks() with cgroup_is_populated() 2015-10-15 16:41:50 -04:00
math-emu
media media updates for v4.3-rc1 2015-09-11 16:42:39 -07:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-09-10 13:53:15 -07:00
pcmcia
ras
rdma Changes for 4.3 2015-09-09 08:33:31 -07:00
rxrpc
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-09-11 19:00:42 -07:00
soc IOMMU Updates for Linux v4.3 2015-09-08 17:22:35 -07:00
sound ALSA: hda - Fix missing inline for dummy snd_hdac_set_codec_wakeup() 2015-09-02 12:24:55 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-09-11 19:00:42 -07:00
trace Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2015-09-11 16:13:47 -07:00
uapi Merge branch 'akpm' (patches from Andrew) 2015-09-11 19:34:09 -07:00
video libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
xen xen: MFN/GFN/BFN terminology changes for 4.3-rc0 2015-09-10 16:21:11 -07:00
Kbuild