Re: drm-current-kmod panics

In message <alpine.BSF.2.21.9999.1912190903390.1198_at_desktop>, Jeff Roberson 
wri
tes:
> On Thu, 19 Dec 2019, Hans Petter Selasky wrote:
>
> > On 2019-12-19 19:40, Cy Schubert wrote:
> >> In message <e9d67a1e-cb80-3c79-704a-5aa3d0ed20ba_at_selasky.org>, Hans Petter
> >> Sela
> >> sky writes:
> >>> On 2019-12-19 17:50, Cy Schubert wrote:
> >>>> Has anyone else had these since Dec 9?
> >>>> 
> >>>> <4>WARN_ON(!mutex_is_locked(&fbc->lock))WARN_ON(!mutex_is_locked(&fbc->
> >>>> lock))
> >>>> panic: page fault
> >>>> cpuid = 1
> >>>> time = 1576772837
> >>>> KDB: stack backtrace:
> >>>> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
> >>>> 0xfffffe007c98b930
> >>>> vpanic() at vpanic+0x17e/frame 0xfffffe007c98b990
> >>>> panic() at panic+0x43/frame 0xfffffe007c98b9f0
> >>>> trap_fatal() at trap_fatal+0x386/frame 0xfffffe007c98ba50
> >>>> trap_pfault() at trap_pfault+0x4f/frame 0xfffffe007c98bac0
> >>>> trap() at trap+0x41b/frame 0xfffffe007c98bbf0
> >>>> calltrap() at calltrap+0x8/frame 0xfffffe007c98bbf0
> >>>> --- trap 0xc, rip = 0x242c52, rsp = 0x7fffffffbe70, rbp = 0x7fffffffbe90
>  
> >>>> --
> >>> -
> >>>> Uptime: 59m7s
> >>>> 
> >>>> It is triggered through random keystrokes or mouse movements.
> >>> 
> >>> Looks like a double fault.
> >>> 
> >>> Did you recompile drm-current-kmod with the latest kernel sources?
> >> 
> >> Yes.
> >> 
> >> 
> >
> > Are you able to get a full backtrace?
>
> Since my recent scheduler commits the following functions now return 
> without the thread lock held:
>
> sched_add()/sched_wakeup()/sched_switch()/mi_switch()/setrunnable()/sleepq_ab
> ort()
>
> I audited drm and linuxkpi for use of these functions.  There was one in 
> the linuxkpi sources that I corrected in the same commit as the change in 
> api.  I don't see any users of these in drm-current-kmod.  It is possible 
> that I have somehow missed it.  I did just commit a fix to cpuset that may 
> be called indirectly somehow.  That fix is r355915.  The first commit of 
> this series was r35579.
>
> If this is at fault I may need some assistance in identifying what the 
> offending call is.  It should show up with INVARIANTS/WITNESS more quickly 
> than a pagefault if so though.

I haven't had any new drm-current-kmod panics since r355915. It's been 
solid. Thank you Jeff.

>
> Thanks,
> Jeff


-- 
Cheers,
Cy Schubert <Cy.Schubert_at_cschubert.com>
FreeBSD UNIX:  <cy_at_FreeBSD.org>   Web:  http://www.FreeBSD.org

	The need of the many outweighs the greed of the few.