diff options
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 125 |
1 files changed, 54 insertions, 71 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index c4901c19668b..7bb274487c89 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -256,68 +256,7 @@ struct cgroup { /* cgroup_root->flags */ enum { - /* - * Unfortunately, cgroup core and various controllers are riddled - * with idiosyncrasies and pointless options. The following flag, - * when set, will force sane behavior - some options are forced on, - * others are disallowed, and some controllers will change their - * hierarchical or other behaviors. - * - * The set of behaviors affected by this flag are still being - * determined and developed and the mount option for this flag is - * prefixed with __DEVEL__. The prefix will be dropped once we - * reach the point where all behaviors are compatible with the - * planned unified hierarchy, which will automatically turn on this - * flag. - * - * The followings are the behaviors currently affected this flag. - * - * - Mount options "noprefix", "xattr", "clone_children", - * "release_agent" and "name" are disallowed. - * - * - When mounting an existing superblock, mount options should - * match. - * - * - Remount is disallowed. - * - * - rename(2) is disallowed. - * - * - "tasks" is removed. Everything should be at process - * granularity. Use "cgroup.procs" instead. - * - * - "cgroup.procs" is not sorted. pids will be unique unless they - * got recycled inbetween reads. - * - * - "release_agent" and "notify_on_release" are removed. - * Replacement notification mechanism will be implemented. - * - * - "cgroup.clone_children" is removed. - * - * - "cgroup.subtree_populated" is available. Its value is 0 if - * the cgroup and its descendants contain no task; otherwise, 1. - * The file also generates kernfs notification which can be - * monitored through poll and [di]notify when the value of the - * file changes. - * - * - If mount is requested with sane_behavior but without any - * subsystem, the default unified hierarchy is mounted. - * - * - cpuset: tasks will be kept in empty cpusets when hotplug happens - * and take masks of ancestors with non-empty cpus/mems, instead of - * being moved to an ancestor. - * - * - cpuset: a task can be moved into an empty cpuset, and again it - * takes masks of ancestors. - * - * - memcg: use_hierarchy is on by default and the cgroup file for - * the flag is not created. - * - * - blkcg: blk-throttle becomes properly hierarchical. - * - * - debug: disallowed on the default hierarchy. - */ - CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), - + CGRP_ROOT_SANE_BEHAVIOR = (1 << 0), /* __DEVEL__sane_behavior specified */ CGRP_ROOT_NOPREFIX = (1 << 1), /* mounted subsystems have no named prefix */ CGRP_ROOT_XATTR = (1 << 2), /* supports extended attributes */ }; @@ -531,20 +470,64 @@ struct cftype { extern struct cgroup_root cgrp_dfl_root; extern struct css_set init_css_set; +/** + * cgroup_on_dfl - test whether a cgroup is on the default hierarchy + * @cgrp: the cgroup of interest + * + * The default hierarchy is the v2 interface of cgroup and this function + * can be used to test whether a cgroup is on the default hierarchy for + * cases where a subsystem should behave differnetly depending on the + * interface version. + * + * The set of behaviors which change on the default hierarchy are still + * being determined and the mount option is prefixed with __DEVEL__. + * + * List of changed behaviors: + * + * - Mount options "noprefix", "xattr", "clone_children", "release_agent" + * and "name" are disallowed. + * + * - When mounting an existing superblock, mount options should match. + * + * - Remount is disallowed. + * + * - rename(2) is disallowed. + * + * - "tasks" is removed. Everything should be at process granularity. Use + * "cgroup.procs" instead. + * + * - "cgroup.procs" is not sorted. pids will be unique unless they got + * recycled inbetween reads. + * + * - "release_agent" and "notify_on_release" are removed. Replacement + * notification mechanism will be implemented. + * + * - "cgroup.clone_children" is removed. + * + * - "cgroup.subtree_populated" is available. Its value is 0 if the cgroup + * and its descendants contain no task; otherwise, 1. The file also + * generates kernfs notification which can be monitored through poll and + * [di]notify when the value of the file changes. + * + * - cpuset: tasks will be kept in empty cpusets when hotplug happens and + * take masks of ancestors with non-empty cpus/mems, instead of being + * moved to an ancestor. + * + * - cpuset: a task can be moved into an empty cpuset, and again it takes + * masks of ancestors. + * + * - memcg: use_hierarchy is on by default and the cgroup file for the flag + * is not created. + * + * - blkcg: blk-throttle becomes properly hierarchical. + * + * - debug: disallowed on the default hierarchy. + */ static inline bool cgroup_on_dfl(const struct cgroup *cgrp) { return cgrp->root == &cgrp_dfl_root; } -/* - * See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This - * function can be called as long as @cgrp is accessible. - */ -static inline bool cgroup_sane_behavior(const struct cgroup *cgrp) -{ - return cgrp->root->flags & CGRP_ROOT_SANE_BEHAVIOR; -} - /* no synchronization, the result can only be used as a hint */ static inline bool cgroup_has_tasks(struct cgroup *cgrp) { |
