cgroup, memcg: allocate cgroup ID from 1

Currently, cgroup->id is allocated from 0, which is always assigned to
the root cgroup; unfortunately, memcg wants to use ID 0 to indicate
invalid IDs and ends up incrementing all IDs by one.

It's reasonable to reserve 0 for special purposes.  This patch updates
cgroup core so that ID 0 is not used and the root cgroups get ID 1.
The ID incrementing is removed form memcg.

Signed-off-by: Tejun Heo <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Acked-by: Li Zefan <[email protected]>

0 files changed, 0 insertions, 0 deletions