Re: [PATCH v11 8/8] vhost: use vhost_tasks for worker threads

[Linus Torvalds]

On Mon, May 15, 2023 at 8:52 AM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> On 5/15/23 9:44?AM, Linus Torvalds wrote:
> >
> > So I think the patch should just look something like the attached.
> > Mike, can you test this on whatever vhost test-suite?
>
> Seems like that didn't get attached...

Blush. I decided to built-test it, and then forgot to attach it. Here.

                  Linus
 kernel/fork.c       | 12 +++---------
 kernel/vhost_task.c |  3 ++-
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index ed4e01daccaa..cd06b137418f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2338,14 +2338,10 @@ __latent_entropy struct task_struct *copy_process(
 		p->flags |= PF_KTHREAD;
 	if (args->user_worker)
 		p->flags |= PF_USER_WORKER;
-	if (args->io_thread) {
-		/*
-		 * Mark us an IO worker, and block any signal that isn't
-		 * fatal or STOP
-		 */
+	if (args->io_thread)
 		p->flags |= PF_IO_WORKER;
+	if (args->ignore_signals)
 		siginitsetinv(&p->blocked, sigmask(SIGKILL)|sigmask(SIGSTOP));
-	}
 
 	if (args->name)
 		strscpy_pad(p->comm, args->name, sizeof(p->comm));
@@ -2517,9 +2513,6 @@ __latent_entropy struct task_struct *copy_process(
 	if (retval)
 		goto bad_fork_cleanup_io;
 
-	if (args->ignore_signals)
-		ignore_signals(p);
-
 	stackleak_task_init(p);
 
 	if (pid != &init_struct_pid) {
@@ -2861,6 +2854,7 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
 		.fn_arg		= arg,
 		.io_thread	= 1,
 		.user_worker	= 1,
+		.ignore_signals	= 1,
 	};
 
 	return copy_process(NULL, 0, node, &args);
diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c
index b7cbd66f889e..2e334b2d7cc4 100644
--- a/kernel/vhost_task.c
+++ b/kernel/vhost_task.c
@@ -75,7 +75,8 @@ struct vhost_task *vhost_task_create(int (*fn)(void *), void *arg,
 				     const char *name)
 {
 	struct kernel_clone_args args = {
-		.flags		= CLONE_FS | CLONE_UNTRACED | CLONE_VM,
+		.flags		= CLONE_FS | CLONE_UNTRACED | CLONE_VM |
+				  CLONE_THREAD | CLONE_SIGHAND,
 		.exit_signal	= 0,
 		.fn		= vhost_task_fn,
 		.name		= name,