blob: 577321264fa4f801528c3eba01b0a5b0b955c77f [file] [log] [blame]
From: Zefan Li <lizefan@huawei.com>
Date: Tue, 9 Aug 2016 11:25:01 +0800
Subject: cpuset: make sure new tasks conform to the current config of the
cpuset
commit 06f4e94898918bcad00cdd4d349313a439d6911e upstream.
A new task inherits cpus_allowed and mems_allowed masks from its parent,
but if someone changes cpuset's config by writing to cpuset.cpus/cpuset.mems
before this new task is inserted into the cgroup's task list, the new task
won't be updated accordingly.
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
kernel/cpuset.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1963,6 +1963,20 @@ static void cpuset_css_free(struct cgrou
kfree(cs);
}
+/*
+ * Make sure the new task conform to the current state of its parent,
+ * which could have been changed by cpuset just after it inherits the
+ * state from the parent and before it sits on the cgroup's task list.
+ */
+void cpuset_fork(struct task_struct *task)
+{
+ if (task_css_is_root(task, cpuset_cgrp_id))
+ return;
+
+ set_cpus_allowed_ptr(task, &current->cpus_allowed);
+ task->mems_allowed = current->mems_allowed;
+}
+
struct cgroup_subsys cpuset_cgrp_subsys = {
.css_alloc = cpuset_css_alloc,
.css_online = cpuset_css_online,
@@ -1971,6 +1985,7 @@ struct cgroup_subsys cpuset_cgrp_subsys
.can_attach = cpuset_can_attach,
.cancel_attach = cpuset_cancel_attach,
.attach = cpuset_attach,
+ .fork = cpuset_fork,
.base_cftypes = files,
.early_init = 1,
};