Re: [PATCH] tests: Disable migration-test

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 21/2/23 18:35, Thomas Huth wrote:
> On 21/02/2023 16.36, Dr. David Alan Gilbert wrote:
>> * Peter Maydell (peter.maydell@linaro.org) wrote:
>>> On Tue, 21 Feb 2023 at 15:21, Dr. David Alan Gilbert
>>> <dgilbert@redhat.com> wrote:
>>>> Damn this is really going to impact the stability of migration if we
>>>> don't regularly test.
>>>> But fundamentally, I've never been able to debug much of the reports
>>>> that come from flakyness in gitlab ci; we're not getting the most basic
>>>> information like which subtest or where we're upto in the test which
>>>> makes it very very hard to debug.
>>>
>>> Right, but if you want more information you need to change the
>>> tests and/or test harness to provide it.
>>
>> I don't think the migration test is doing anything odd in that respect;
>> We've just got a bunch of qtest tests; having a test framework which
>> doesn't tell you which test failed is very difficult.
> 
> FWIW, I just saw another failure, on a s390x host,
> last lines of the log are:
> 
> ok 10 /s390x/migration/postcopy/recovery/tls/psk
> # End of tls tests
> # End of recovery tests
> # Start of preempt tests
> # starting QEMU: exec ./qemu-system-s390x -qtest 
> unix:/tmp/qtest-7847.sock -qtest-log /dev/null -chardev 
> socket,path=/tmp/qtest-7847.qmp,id=char0 -mon chardev=char0,mode=control 
> -display none -accel kvm -accel tcg -name source,debug-threads=on -m 
> 128M -serial file:/tmp/migration-test-03MJ01/src_serial -bios 
> /tmp/migration-test-03MJ01/bootsect    -accel qtest
> # starting QEMU: exec ./qemu-system-s390x -qtest 
> unix:/tmp/qtest-7847.sock -qtest-log /dev/null -chardev 
> socket,path=/tmp/qtest-7847.qmp,id=char0 -mon chardev=char0,mode=control 
> -display none -accel kvm -accel tcg -name target,debug-threads=on -m 
> 128M -serial file:/tmp/migration-test-03MJ01/dest_serial -incoming 
> unix:/tmp/migration-test-03MJ01/migsocket -bios 
> /tmp/migration-test-03MJ01/bootsect    -accel qtest
> ok 11 /s390x/migration/postcopy/preempt/plain
> # Start of recovery tests
> # starting QEMU: exec ./qemu-system-s390x -qtest 
> unix:/tmp/qtest-7847.sock -qtest-log /dev/null -chardev 
> socket,path=/tmp/qtest-7847.qmp,id=char0 -mon chardev=char0,mode=control 
> -display none -accel kvm -accel tcg -name source,debug-threads=on -m 
> 128M -serial file:/tmp/migration-test-03MJ01/src_serial -bios 
> /tmp/migration-test-03MJ01/bootsect   2>/dev/null -accel qtest
> # starting QEMU: exec ./qemu-system-s390x -qtest 
> unix:/tmp/qtest-7847.sock -qtest-log /dev/null -chardev 
> socket,path=/tmp/qtest-7847.qmp,id=char0 -mon chardev=char0,mode=control 
> -display none -accel kvm -accel tcg -name target,debug-threads=on -m 
> 128M -serial file:/tmp/migration-test-03MJ01/dest_serial -incoming 
> unix:/tmp/migration-test-03MJ01/migsocket -bios 
> /tmp/migration-test-03MJ01/bootsect   2>/dev/null -accel qtest
> ----------------------------------- stderr 
> -----------------------------------
> Broken pipe
> ../tests/qtest/libqtest.c:193: kill_qemu() detected QEMU death from 
> signal 11 (Segmentation fault) (core dumped)
> 
> (test program exited with status code -6)

I get some of these too, but qtest parent debug info isn't very helpful,
I'd rather get the child info. I tried this some time ago but per Paolo
it wasn't correct: 
https://lore.kernel.org/qemu-devel/20200707031920.17428-1-f4bug@amsat.org/
I still use this patch when running my tests as it helps me to
understand where the child crash, so I didn't really looked at
what is the correct fix.