diff options
| author | Tejun Heo <tj@kernel.org> | 2016-03-03 09:58:01 -0500 |
|---|---|---|
| committer | Michael Bestas <mkbestas@lineageos.org> | 2022-04-19 00:51:00 +0300 |
| commit | f0a1738a16fddc8b9583a7bfe2c4bdd26f522bbc (patch) | |
| tree | 7f850783df0d59751281fd9c7f31e5c0f578858e | |
| parent | 8f1e56d63f055d1a370690179871d39f4bb5e848 (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>
Signed-off-by: Chatur27 <jasonbright2709@gmail.com>
| -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 07d5c426659a..5704f46f2851 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1935,10 +1935,11 @@ 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; |