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| author | Tejun Heo <tj@kernel.org> | 2022-07-29 13:10:16 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2022-08-15 11:16:47 -1000 |
| commit | 7f203bc89eb66d6afde7eae91347fc0352090cc3 (patch) | |
| tree | a8a4f1fa1203a0200089982587709f334b0ff968 /kernel/cgroup | |
| parent | 568035b01cfb107af8d2e4bd2fb9aea22cf5b868 (diff) | |
| download | linux-7f203bc89eb66d6afde7eae91347fc0352090cc3.tar.bz2 | |
cgroup: Replace cgroup->ancestor_ids[] with ->ancestors[]
Every cgroup knows all its ancestors through its ->ancestor_ids[]. There's
no advantage to remembering the IDs instead of the pointers directly and
this makes the array useless for finding an actual ancestor cgroup forcing
cgroup_ancestor() to iteratively walk up the hierarchy instead. Let's
replace cgroup->ancestor_ids[] with ->ancestors[] and remove the walking-up
from cgroup_ancestor().
While at it, improve comments around cgroup_root->cgrp_ancestor_storage.
This patch shouldn't cause user-visible behavior differences.
v2: Update cgroup_ancestor() to use ->ancestors[].
v3: cgroup_root->cgrp_ancestor_storage's type is updated to match
cgroup->ancestors[]. Better comments.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index ffaccd6373f1..627ff0f07da7 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2049,7 +2049,7 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) } root_cgrp->kn = kernfs_root_to_node(root->kf_root); WARN_ON_ONCE(cgroup_ino(root_cgrp) != 1); - root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp); + root_cgrp->ancestors[0] = root_cgrp; ret = css_populate_dir(&root_cgrp->self); if (ret) @@ -5400,8 +5400,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, int ret; /* allocate the cgroup and its ID, 0 is reserved for the root */ - cgrp = kzalloc(struct_size(cgrp, ancestor_ids, (level + 1)), - GFP_KERNEL); + cgrp = kzalloc(struct_size(cgrp, ancestors, (level + 1)), GFP_KERNEL); if (!cgrp) return ERR_PTR(-ENOMEM); @@ -5453,7 +5452,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent, const char *name, spin_lock_irq(&css_set_lock); for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) { - cgrp->ancestor_ids[tcgrp->level] = cgroup_id(tcgrp); + cgrp->ancestors[tcgrp->level] = tcgrp; if (tcgrp != cgrp) { tcgrp->nr_descendants++; |