On Wed, Dec 11, 2024 at 1:53 AM Stefano Garzarella [off-list ref] wrote:

On Wed, Dec 11, 2024 at 12:41:42AM +0800, Cindy Lu wrote:

quoted

Add back the previously removed cgroup function to support the kthread

nit: missing . at the end

will fix this

quoted

The biggest change for this part is in vhost_attach_cgroups() and
vhost_attach_task_to_cgroups().

It's not clear what the big change is, is there a piece missing?

sure, I will rewrite this part to make it more clear
Thanks
cindy

quoted

The old function was remove in

s/remove/removed

BTW which is the old function?

I will add this information
Thanks
cindy

quoted

commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads")

Signed-off-by: Cindy Lu <redacted>
---
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)

This function looks renamed, should we mention in the commit
description?

quoted

+{
+      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);

IIUC this block is the old "vhost_dev_flush", right?

Maybe we should mention also that in the commit description.

sure, will add these informations
Thanks
cindy

quoted

+
+      return attach.ret;
+}
+
/* Caller should have device mutex */
bool vhost_dev_has_owner(struct vhost_dev *dev)
{
--
2.45.0