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| author | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:13 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-05-04 15:09:13 -0400 |
| commit | 7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b (patch) | |
| tree | 0811810b37ff735921b689aa1ca273ecf253e29c /kernel/cgroup.c | |
| parent | 69dfa00ccb72a37f3810687ca110e5a8154c6eed (diff) | |
| download | lwn-7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b.tar.gz lwn-7d699ddb2b181a2c76e5ea18b1bdf102c4bebe4b.zip | |
cgroup, memcg: allocate cgroup ID from 1
Currently, cgroup->id is allocated from 0, which is always assigned to
the root cgroup; unfortunately, memcg wants to use ID 0 to indicate
invalid IDs and ends up incrementing all IDs by one.
It's reasonable to reserve 0 for special purposes. This patch updates
cgroup core so that ID 0 is not used and the root cgroups get ID 1.
The ID incrementing is removed form memcg.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 21667f396a1e..3fa0463e74bb 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1531,7 +1531,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask) lockdep_assert_held(&cgroup_tree_mutex); lockdep_assert_held(&cgroup_mutex); - ret = idr_alloc(&root->cgroup_idr, root_cgrp, 0, 1, GFP_KERNEL); + ret = idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL); if (ret < 0) goto out; root_cgrp->id = ret; @@ -4225,7 +4225,7 @@ static long cgroup_create(struct cgroup *parent, const char *name, * Temporarily set the pointer to NULL, so idr_find() won't return * a half-baked cgroup. */ - cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL); + cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL); if (cgrp->id < 0) { err = -ENOMEM; goto err_unlock; |