diff options
| author | Tejun Heo <tj@kernel.org> | 2016-03-03 09:58:01 -0500 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2016-03-03 09:58:01 -0500 |
| commit | 04313591ae487da8b5781a0d8d444073a3fdee0d (patch) | |
| tree | eb0582020cd0369d8767c813149b9eec7dddde8e /kernel/cgroup.c | |
| parent | 5ced2518bd3e3a4f01e2122122211f217cd99f4f (diff) | |
cgroup: allocate 2x cgrp_cset_links when setting up a new root
During prep, cgroup_setup_root() allocates cgrp_cset_links matching
the number of existing css_sets to later link the new root. This is
fine for now as the only operation which can happen inbetween is
rebind_subsystems() and rebinding of empty subsystems doesn't create
new css_sets.
However, while not yet allowed, with the recent reimplementation,
rebind_subsystems() can rebind subsystems with descendant csses and
thus can create new css_sets. This patch makes cgroup_setup_root()
allocate 2x of the existing css_sets so that later use of live
subsystem rebinding doesn't blow up.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 58e02e9aa970..40ed329482dd 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1915,10 +1915,11 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) /* * We're accessing css_set_count without locking css_set_lock here, * but that's OK - it can only be increased by someone holding - * cgroup_lock, and that's us. The worst that can happen is that we - * have some link structures left over + * cgroup_lock, and that's us. Later rebinding may disable + * controllers on the default hierarchy and thus create new csets, + * which can't be more than the existing ones. Allocate 2x. */ - ret = allocate_cgrp_cset_links(css_set_count, &tmp_links); + ret = allocate_cgrp_cset_links(2 * css_set_count, &tmp_links); if (ret) goto cancel_ref; |