[OE-core] Yocto Project Status WW47’17

[Robert Yang]

On 11/28/2017 03:49 PM, Robert Yang wrote:
> 
> On 11/23/2017 06:20 PM, Richard Purdie wrote:
>> On Mon, 2017-11-20 at 20:22 -0500, Randy MacLeod wrote:
>>>> o   Issues with 4.13.10 host kernels booting kvm x86 guests on
>>>> Tumbleweed (Suse) and Fedora 26 (attempting to see if 4.13.12
>>>> helps)
>>> Robert, can you test Fedora 26. It would help to have a defect open
>>> with steps to reproduce or
>>> something about the typical workflow/ build time/ day of the week/
>>> phase of the moon.
>>
>> We have some further data:
>>
>> a) The issue occurs on 4.13.12
>>
>> rpurdie at tumbleweed:/tmp> cat /proc/version
>> Linux version 4.13.12-1-vanilla (geeko at buildhost) (gcc version 7.2.1 20171020 
>> [gcc-7-branch revision 253932] (SUSE Linux)) #1 SMP PREEMPT Wed Nov 8 11:21:09 
>> UTC 2017 (9151c66)
>>
>> b) The hang usually occurs at the TIMER line in the kernel logs but can
>> occur after booting into userspace around the udevd line, or
>> occasionally later in the boot process.
>>
>> c) The similarity between this and the ppc bug I worked on make me
>> strongly suspect qemu's timers are stopping firing and the guest is
>> sitting in the idle loop.
>>
>> d) I do now have a way to brute force the hangs at will. The attached
>> "runqemu-parallel.py" script runs 50 qemus in parallel. In around 45s I
>> had 10 hung on the autobuilder. I can provide more info on using that
>> script if its not obvious. It does assume my recent master changes to
>> the qemuconf files so we don't need to run bitbake -e to run runqemu.
>>
>> This could well be the same kind of locking issue we saw on ppc. I'll
>> continue to look into that.
>>
>> Hopefully this extra information will put us on a good track to
>> resolving it now. It is continuing to break builds and stop patch
>> merging.
> 
> I modified the script to run on my host (I used qemux86, not qemux86-64,
> the later one is still in building) (Up to date Fedora 26, the kernel
> is 4.13.13):
> 
> $ cat /proc/version
> Linux version 4.13.13-200.fc26.x86_64 
> (mockbuild at bkernel01.phx2.fedoraproject.org) (gcc version 7.2.1 20170915 (Red 
> Hat 7.2.1-2) (GCC)) #1 SMP Wed Nov 15 15:46:36 UTC 2017
> 
> But didn't see any hangs after 10 minutes, all the qemus reached login. So maybe
> it had been fixed on 4.13.13 ?

I tested qemux86-64, the boot became very slow (just like hang), no one booted
after about 2 hours (still in booting). And it only happened when
use qemux86-64 + kvm:

# Works
$ runqemu tmp/deploy/images/qemux86-64/ nographic snapshot

# Doesn't work, like hang:
$ runqemu tmp/deploy/images/qemux86-64/ nographic snapshot kvm

// Robert

> 
> // Robert
> 
>>
>> Cheers,
>>
>> Richard
>>