Re: [RFC PATCH v2 05/18] sched: add task flag for preempt IRQ tracking

Andy Lutomirski
2016-04-29T18:07:17Z

On Thu, Apr 28, 2016 at 1:44 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> A preempted function might not have had a chance to save the frame
> pointer to the stack yet, which can result in its caller getting skipped
> on a stack trace.
>
> Add a flag to indicate when the task has been preempted so that stack
> dump code can determine whether the stack trace is reliable.

I think I like this, but how do you handle the rather similar case in
which a task goes to sleep because it's waiting on IO that happened in
response to get_user, put_user, copy_from_user, etc?

--Andy