On Thu, Apr 24, 2025 at 12:25:42PM -0400, Steven Rostedt wrote:
> +static int deferred_request(struct perf_event *event)
> +{
> + struct callback_head *work = &event->pending_unwind_work;
> + int pending;
> + int ret;
> +
> + if (!current->mm || !user_mode(task_pt_regs(current)))
> + return -EINVAL;
> +
> + if (in_nmi())
> + return deferred_request_nmi(event);
> +
> + guard(irqsave)();
> +
> + /* callback already pending? */
> + pending = READ_ONCE(event->pending_unwind_callback);
> + if (pending)
> + return 1;
> +
> + /* Claim the work unless an NMI just now swooped in to do so. */
> + if (!try_cmpxchg(&event->pending_unwind_callback, &pending, 1))
> + return 1;
> +
> + /* The work has been claimed, now schedule it. */
> + ret = task_work_add(current, work, TWA_RESUME);
> + if (WARN_ON_ONCE(ret)) {
> + WRITE_ONCE(event->pending_unwind_callback, 0);
> + return ret;
> + }
> + return 0;
> +}
You have whitespace issues ...
