DRM-current-kmod is still a problem at r353339

[Mark Johnston]

On Thu, Oct 17, 2019 at 10:31:12PM +0200, Niclas Zeising wrote:
> On 2019-10-17 21:53, markj at freebsd.org wrote:
> > On Thu, Oct 17, 2019 at 03:03:51PM +0200, Niclas Zeising wrote:
> >> On 2019-10-16 18:57, Neel Chauhan wrote:
> >>> While drm-current-kmod worked for a little while, it broke with r353645.
> >>>
> >>> https://i.imgur.com/Q5nYZf2.jpg
> >>>
> >>> I'm using the same HP Spectre that I used earlier (where it worked and
> >>> where it panicked).
> >>>
> >>
> >> That commit looks unrelated, it touches the wbwd and superio drivers,
> >> nothing else.  Any chance you can bisect exactly which revision that
> >> caused the new issues?
> > 
> > I believe it was the recent work on the vm page busy state, r353539
> > specifically.  This patch should fix it; we don't yet have a
> > __FreeBSD_version number bump on which to gate the patch.
> > 
> > diff --git a/linuxkpi/gplv2/src/linux_page.c b/linuxkpi/gplv2/src/linux_page.c
> > index e2b85c45c..060ae85ed 100644
> > --- a/linuxkpi/gplv2/src/linux_page.c
> > +++ b/linuxkpi/gplv2/src/linux_page.c
> > @@ -239,7 +239,7 @@ retry:
> >   			page = vm_page_lookup(devobj, i);
> >   			if (page == NULL)
> >   				continue;
> > -			if (vm_page_sleep_if_busy(page, "linuxkpi"))
> > +			if (!vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL))
> >   				goto retry;
> >   			cdev_pager_free_page(devobj, page);
> >   		}
> 
> Hi!
> Hopefully someone can confirm that this patch to drm-current-kmod or 
> drm-devel-kmod fixes the issue.  I won't be able to work on this before 
> the weekend at the earliest, I'm afraid.
> Mark, is it possible to get a belated version bump for this fix, and 
> what changed to require it?

I committed the bump and verified the patch on amdgpu.  Here are some
PRs for the drivers:

https://github.com/FreeBSDDesktop/kms-drm/pull/180
https://github.com/FreeBSDDesktop/kms-drm/pull/181