From: Tejun Heo Date: Fri, 9 Nov 2012 17:12:29 +0000 (-0800) Subject: cgroup: add cgroup_subsys->post_create() X-Git-Tag: omap-for-v3.8/fixes-for-merge-window-v4-signed~57^2~43 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a8638030f668884720b8f4456448d0ce33952b05;p=pandora-kernel.git cgroup: add cgroup_subsys->post_create() Currently, there's no way for a controller to find out whether a new cgroup finished all ->create() allocatinos successfully and is considered "live" by cgroup. This becomes a problem later when we add generic descendants walking to cgroup which can be used by controllers as controllers don't have a synchronization point where it can synchronize against new cgroups appearing in such walks. This patch adds ->post_create(). It's called after all ->create() succeeded and the cgroup is linked into the generic cgroup hierarchy. This plays the counterpart of ->pre_destroy(). When used in combination with the to-be-added generic descendant iterators, ->post_create() can be used to implement reliable state inheritance. It will be explained with the descendant iterators. v2: Added a paragraph about its future use w/ descendant iterators per Michal. v3: Forgot to add ->post_create() invocation to cgroup_load_subsys(). Fixed. Signed-off-by: Tejun Heo Acked-by: Michal Hocko Reviewed-by: KAMEZAWA Hiroyuki Acked-by: Li Zefan Cc: Glauber Costa --- Reading git-diff-tree failed