Hello, Linus.
I made a mistake while removing cgroup task list lazy init
optimization making the root cgroup.procs show entries for the
init_tasks. The 0 entries doesn't cause critical failures but does
make systemd print out warning messages during boot. Fix it by
omitting init_tasks as they should be.
Thanks.
The following changes since commit 39bed42de2e7d74686a2d5a45638d6a5d7e7d473:
Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma (2020-01-29 19:56:50 -0800)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-5.6-fixes
for you to fetch changes up to 0cd9d33ace336bc424fc30944aa3defd6786e4fe:
cgroup: init_tasks shouldn't be linked to the root cgroup (2020-01-30 11:37:33 -0500)
----------------------------------------------------------------
Tejun Heo (1):
cgroup: init_tasks shouldn't be linked to the root cgroup
kernel/cgroup/cgroup.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b3744872263e..cf8a36bdf5c8 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5932,11 +5932,14 @@ void cgroup_post_fork(struct task_struct *child)
spin_lock_irq(&css_set_lock);
- WARN_ON_ONCE(!list_empty(&child->cg_list));
- cset = task_css_set(current); /* current is @child's parent */
- get_css_set(cset);
- cset->nr_tasks++;
- css_set_move_task(child, NULL, cset, false);
+ /* init tasks are special, only link regular threads */
+ if (likely(child->pid)) {
+ WARN_ON_ONCE(!list_empty(&child->cg_list));
+ cset = task_css_set(current); /* current is @child's parent */
+ get_css_set(cset);
+ cset->nr_tasks++;
+ css_set_move_task(child, NULL, cset, false);
+ }
/*
* If the cgroup has to be frozen, the new task has too. Let's set
