Re: EARLY_AP_STARTUP hangs during boot

On Tue, 31 May 2016 13:10:06 -0700
John Baldwin <jhb_at_freebsd.org> wrote:

> On Saturday, May 28, 2016 02:11:41 PM Gary Jennejohn wrote:
> > On Fri, 27 May 2016 09:50:05 +0200
> > Gary Jennejohn <gljennjohn_at_gmail.com> wrote:
> >   
> > > On Thu, 26 May 2016 16:54:35 -0700
> > > John Baldwin <jhb_at_freebsd.org> wrote:
> > >   
> > > > On Tuesday, May 17, 2016 06:47:41 PM Gary Jennejohn wrote:    
> > > > > On Mon, 16 May 2016 10:54:19 -0700
> > > > > John Baldwin <jhb_at_freebsd.org> wrote:
> > > > >       
> > > > > > On Monday, May 16, 2016 12:22:42 PM Gary Jennejohn wrote:      
> > > > > > > I tried out EARLY_AP_STARTUP, but the kernel hangs and I can't
> > > > > > > break into DDB.
> > > > > > > 
> > > > > > > I did a verbose boot and the last lines I see are related to routing
> > > > > > > MSI-X to various local APIC vectors.  I copied the last few lines and
> > > > > > > they look like this:
> > > > > > > 
> > > > > > > msi: routing MSI-X IRQ 256 to local APIC 2 vector 48
> > > > > > > msi: routing MSI-X IRQ 257 to local APIC 3 vector 48
> > > > > > > msi: routing MSI-X IRQ 258 to local APIC 4 vector 48
> > > > > > > msi: routing MSI-X IRQ 256 to local APIC 0 vector 49      
> > > > >          ^^^^^^^ Assigning      
> > > > > > > 
> > > > > > > I tried disabling msi and msix in /boot/loader.conf, but the settings
> > > > > > > were ignored (probabaly too early).        
> > > > > > 
> > > > > > No, those settings are not too early.  However, the routing to different
> > > > > > CPUs now happens earlier than it used to.  What is the line before the
> > > > > > MSI lines?  You can take a picture with your phone/camera if that's simplest.
> > > > > >       
> > > > > 
> > > > > Here a few lines before the MSI routing happens:
> > > > > 
> > > > > hpet0: <High Precision Event Timer> iomem 0xfed00000-0xfed003ff irq 0,8 on acpi0
> > > > > hpet0: vendor 0x4353, rev 0x1, 14318180 Hz, 3 timers, legacy route
> > > > > hpet0: t0 : irqs 0x00c0ff (0), MSI, periodic
> > > > > hpet0: t1 : irqs 0x00c0ff (0), MSI, periodic
> > > > > hpet0: t2 : irqs 0x00c0ff (0), MSI, periodic
> > > > > Timecounter "HPET" frequency 14318180 Hz quality 950      
> > > > 
> > > > The assigning message means it is in the loop using
> > > > bus_bind_intr() to setup per-CPU timers.  Can you please try
> > > > setting 'hint.hpet.0.per_cpu=0' at the loader prompt to see if
> > > > disabling the use of per-CPU timers allows you to boot?
> > > >     
> > > 
> > > Something has changed since the last time I generated a kernel with
> > > this option.
> > > 
> > > Now I get a NULL-pointer dereference in the kernel, doesn't matter
> > > whether I set the hint or not.
> > >   
> > 
> > OK, now that the startup has been fixed, I tried setting the hint at
> > the loader prompt, but the kenel hangs in exactly the same place as
> > before.  I actually booted twice to make certain I hadn't made a
> > typo when setting the hint.  
> 
> Humm, it shouldn't be calling bus_bind_intr() if the hint is set.  Actually,
> I guess it just binds them all to first CPU if per-CPU timers aren't set.
> Can you add debug printfs to hpet_attach() in sys/dev/acpica/acpi_hpet.c to
> narrow down which line in that function it hangs after?
> 
> Another option to try is to add the following to your kernel config:
> 
> options  	KTR
> options  	KTR_COMPILE=KTR_PROC
> options 		KTR_MASK=KTR_PROC
> options  	KTR_VERBOSE=1
> 
> this will spew a lot of crap to the screen, but if it stops spewing when it
> hangs then it might be tell us where the system is hung.  If you have any way
> to configure a serial console then this would also be useful even if it spews
> constantly when it is hung (assuming you could log the output of the serial
> console).
> 

I used the KTR options.

After the Timecounter "HPET" frequency 14318180 Hz quality 950 I see

cpu0 mi_switch: old thread 10000 (swapper)
cpu0 mi_switch: new thread 10022 (if_config_tqg_0)
cpu0 sleep_broadcast(0x80002f9a600, 0)
cpu0 msleep_spin: old thread 100022
cpu0 mi_switch: old thread 10022
cpu0 mi_switch: new thread 10016 (if_io_tqg_0)
cpu0 sleep_broadcast(0x80002f9a780, 0)
cpu0 msleep_spin: old thread 10016
cpu0 mi_switch: old thread 10016
cpu0 fork_exit: new thread 0x80004239510 (td_sched 0x8000042399d8, pid
10, idle: cpu0)

And that's all that came out, really not very much at all.

-- 
Gary Jennejohn