[PATCH v4 3/8] vhost: Add the cgroup related function

Cindy Lu
2024-12-10T16:45:25Z

Add back the previously removed cgroup function to support the kthread
The biggest change for this part is in vhost_attach_cgroups() and
vhost_attach_task_to_cgroups().

The old function was remove in
commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads")

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
drivers/vhost/vhost.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 1feba29abf95..812dfd218bc2 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -22,6 +22,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
+#include <linux/cgroup.h>
#include <linux/module.h>
#include <linux/sort.h>
#include <linux/sched/mm.h>
@@ -620,6 +621,38 @@ long vhost_dev_check_owner(struct vhost_dev *dev)
}
EXPORT_SYMBOL_GPL(vhost_dev_check_owner);

+struct vhost_attach_cgroups_struct {
+ struct vhost_work work;
+ struct task_struct *owner;
+ int ret;
+};
+
+static void vhost_attach_cgroups_work(struct vhost_work *work)
+{
+ struct vhost_attach_cgroups_struct *s;
+
+ s = container_of(work, struct vhost_attach_cgroups_struct, work);
+ s->ret = cgroup_attach_task_all(s->owner, current);
+}
+
+static int vhost_attach_task_to_cgroups(struct vhost_worker *worker)
+{
+ struct vhost_flush_struct flush;
+ struct vhost_attach_cgroups_struct attach;
+
+ attach.owner = current;
+
+ vhost_work_init(&attach.work, vhost_attach_cgroups_work);
+ vhost_worker_queue(worker, &attach.work);
+
+ init_completion(&flush.wait_event);
+ vhost_work_init(&flush.work, vhost_flush_work);
+ vhost_worker_queue(worker, &flush.work);
+ wait_for_completion(&flush.wait_event);
+
+ return attach.ret;
+}
+
/* Caller should have device mutex */
bool vhost_dev_has_owner(struct vhost_dev *dev)
{
--
2.45.0