From 8e4ec90701efec7f2814c89b398d6d4272636814 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 20 Oct 2025 07:55:55 -1000 Subject: freezer: Clarify that only cgroup1 freezer uses PM freezer cgroup1 freezer piggybacks on the PM freezer, which inadvertently allowed userspace to produce uninterruptible tasks at will. To avoid the issue, cgroup2 freezer switched to a separate job control based mechanism. While this happened a long time ago, the code and comment haven't been updated making it confusing to people who aren't familiar with the history. Rename cgroup_freezing() to cgroup1_freezing() and update comments on top of freezing() and frozen() to clarify that cgroup2 freezer isn't covered by the PM freezer mechanism. Signed-off-by: Tejun Heo Suggested-by: Qu Wenruo Link: https://patch.msgid.link/aPZ3q6Hm865NicBC@slm.duckdns.org Signed-off-by: Rafael J. Wysocki --- kernel/cgroup/legacy_freezer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/cgroup') diff --git a/kernel/cgroup/legacy_freezer.c b/kernel/cgroup/legacy_freezer.c index dd9417425d92..915b02f65980 100644 --- a/kernel/cgroup/legacy_freezer.c +++ b/kernel/cgroup/legacy_freezer.c @@ -63,7 +63,7 @@ static struct freezer *parent_freezer(struct freezer *freezer) return css_freezer(freezer->css.parent); } -bool cgroup_freezing(struct task_struct *task) +bool cgroup1_freezing(struct task_struct *task) { bool ret; -- cgit v1.2.3