Re: mlockall and mmap of IO devices don't mix

Joe Korty
2003-10-03T22:56:45Z

On Fri, Oct 03, 2003 at 03:23:49PM -0700, Andrew Morton wrote:
> Joe Korty <joe.korty@ccur.com> wrote:
> >
> > 2.6.0-test6: the use of mlockall(2) in a process that has mmap(2)ed
> > the registers of an IO device will hang that process uninterruptibly.
> > The task runs in an infinite loop in get_user_pages(), invoking
> > follow_page() forever.
>
> whoops.
>
> I think the right fix is in get_user_pages(): if the region is VM_IO then
> don't call follow_page() at all.
>
> Something like this?

Sigh. No go; it *looks* good but my app still locks up....

Regards,
Joe