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| author | Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> | 2010-03-10 15:22:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-12 15:52:35 -0800 |
| commit | 2468c7234b366eeb799ee0648cb58f9cba394a54 (patch) | |
| tree | 050d7ea224b975eb71b05bf472f14f4c7bb13670 /Documentation | |
| parent | 5ce9f07bf1bed9a1f9886373ad0b149294f84c25 (diff) | |
| download | lwn-2468c7234b366eeb799ee0648cb58f9cba394a54.tar.gz lwn-2468c7234b366eeb799ee0648cb58f9cba394a54.zip | |
cgroup: introduce cancel_attach()
Add cancel_attach() operation to struct cgroup_subsys. cancel_attach()
can be used when can_attach() operation prepares something for the subsys,
but we should rollback what can_attach() operation has prepared if attach
task fails after we've succeeded in can_attach().
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/cgroups/cgroups.txt | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 0b33bfe7dde9..d45082653e3d 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -536,10 +536,21 @@ returns an error, this will abort the attach operation. If a NULL task is passed, then a successful result indicates that *any* unspecified task can be moved into the cgroup. Note that this isn't called on a fork. If this method returns 0 (success) then this should -remain valid while the caller holds cgroup_mutex. If threadgroup is +remain valid while the caller holds cgroup_mutex and it is ensured that either +attach() or cancel_attach() will be called in future. If threadgroup is true, then a successful result indicates that all threads in the given thread's threadgroup can be moved together. +void cancel_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct task_struct *task, bool threadgroup) +(cgroup_mutex held by caller) + +Called when a task attach operation has failed after can_attach() has succeeded. +A subsystem whose can_attach() has some side-effects should provide this +function, so that the subsytem can implement a rollback. If not, not necessary. +This will be called only about subsystems whose can_attach() operation have +succeeded. + void attach(struct cgroup_subsys *ss, struct cgroup *cgrp, struct cgroup *old_cgrp, struct task_struct *task, bool threadgroup) |