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| author |   Tejun Heo <tj@kernel.org> | 2019-11-04 15:54:30 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2019-11-12 08:18:04 -0800 |
| commit | 743210386c0354a2f8ef3d697353c7d8477fa81d (patch) | |
| tree | ac8071135c3e67ff425391540eb88c7dc343afb7 /include/linux/cgroup.h | |
| parent | kernfs: use 64bit inos if ino_t is 64bit (diff) | |
| download | linux-dev-743210386c0354a2f8ef3d697353c7d8477fa81d.tar.xz linux-dev-743210386c0354a2f8ef3d697353c7d8477fa81d.zip | |
cgroup: use cgrp->kn->id as the cgroup ID
cgroup ID is currently allocated using a dedicated per-hierarchy idr
and used internally and exposed through tracepoints and bpf. This is
confusing because there are tracepoints and other interfaces which use
the cgroupfs ino as IDs.
The preceding changes made kn->id exposed as ino as 64bit ino on
supported archs or ino+gen (low 32bits as ino, high gen). There's no
reason for cgroup to use different IDs. The kernfs IDs are unique and
userland can easily discover them and map them back to paths using
standard file operations.
This patch replaces cgroup IDs with kernfs IDs.
* cgroup_id() is added and all cgroup ID users are converted to use it.
* kernfs_node creation is moved to earlier during cgroup init so that
cgroup_id() is available during init.
* While at it, s/cgroup/cgrp/ in psi helpers for consistency.
* Fallback ID value is changed to 1 to be consistent with root cgroup
ID.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 815fff49d555..d7ddebd0cdec 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -304,6 +304,11 @@ void css_task_iter_end(struct css_task_iter *it); * Inline functions. */ +static inline u64 cgroup_id(struct cgroup *cgrp) +{ + return cgrp->kn->id; +} + /** * css_get - obtain a reference on the specified css * @css: target css @@ -565,7 +570,7 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp, { if (cgrp->root != ancestor->root || cgrp->level < ancestor->level) return false; - return cgrp->ancestor_ids[ancestor->level] == ancestor->id; + return cgrp->ancestor_ids[ancestor->level] == cgroup_id(ancestor); } /** @@ -687,17 +692,13 @@ static inline void cgroup_kthread_ready(void) current->no_cgroup_migration = 0; } -static inline u64 cgroup_get_kernfs_id(struct cgroup *cgrp) -{ - return cgrp->kn->id; -} - void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen); #else /* !CONFIG_CGROUPS */ struct cgroup_subsys_state; struct cgroup; +static inline u64 cgroup_id(struct cgroup *cgrp) { return 1; } static inline void css_get(struct cgroup_subsys_state *css) {} static inline void css_put(struct cgroup_subsys_state *css) {} static inline int cgroup_attach_task_all(struct task_struct *from, @@ -717,10 +718,6 @@ static inline int cgroup_init_early(void) { return 0; } static inline int cgroup_init(void) { return 0; } static inline void cgroup_init_kthreadd(void) {} static inline void cgroup_kthread_ready(void) {} -static inline union u64 cgroup_get_kernfs_id(struct cgroup *cgrp) -{ - return 0; -} static inline struct cgroup *cgroup_parent(struct cgroup *cgrp) { |