Hi Dan,
On Wed, Aug 04, 2021 at 12:57:25PM +0300, Dan Carpenter wrote:
> These sleeping in atomic static checker warnings come with a lot of
> caveats because the call tree is very long and it's easy to have false
> positives.
>
> --> vc_raw_handle_exception()
> --> vc_forward_exception()
> --> exc_page_fault()
>
> Page faults always sleep right?
No, page faults do no always sleep, only when IO needs to be done to
fulfill the page fault request. In this case, the page-fault handler
will never sleep, because it is called with preemption disabled. The
page-fault handler can detect this and just do nothing. The #VC handler
will return for re-fault in this case.
Hope that helps,
Joerg
