Re: [PATCH v3 00/29] PowerPC interrupt rework

[Daniel Henrique Barboza]

Matheus,

I did some digging yesterday. There are 2 distinct things happening:

- the apparent problem with the avocado test. After doing more and more tests
it seems like the test failure rate is lower than 10%. With a simple script
to exercise it in my laptop:

n=1
while [ 1 ]; do
        make -j check-avocado \
                
AVOCADO_TESTS='tests/avocado/replay_kernel.py:ReplayKernelNormal.test_ppc64_e500'
 ;
        if [ $? -ne 0 ]; then
                echo "test failed after $n interactions"
                exit 1
        fi
        ((n=n+1))
done

In master I managed to get up to 100+ runs without failure. Sometimes I get 90,
50, 30 runs before failure and so on. This is an OK failure rate in my opinion,
so if any code contribution does not dramatically increase this failure rate I'm
fine with it. This also means that I'll not be skipping the test.

- back to this series, I couldn't manage to get a single successful run with
patch 27 applied. On the other hand, running the aforementioned script with
patches 1-26 I just got 96 test runs before the first failure. This is enough
evidence for me to believe that, yeah, patch 27 is really doing something that 
is
messing with the icount replay for e500 one way or the other.


All that said, patches 1-26 are queued in ppc-next.


On 10/20/22 10:40, Matheus K. Ferst wrote:
> On 20/10/2022 08:18, Daniel Henrique Barboza wrote:
> > On 10/19/22 18:55, Daniel Henrique Barboza wrote:
> > > Matheus,
> > >
> > > This series fails 'make check-avocado' in an e500 test. This is the error 
> > > output:
> >
> > Scrap that.
> >
> > This avocado test is also failing on master 10% of the time, give or take.
> > It might be case that patch 27 makes the failure more consistent, but I can't
> > say it's the culprit.
> >
> >
> > I'll take a closer look and see if I can diagnose one particular commit that
> > is making the patch fail 1 out of 10 times. It can be case where I might need
> > to skip the test altogether.
>
> Nice catch. I guess we need a gen_icount_io_start before calling 
> helper_ppc_maybe_interrupt, so maybe it's better to make a 
> gen_ppc_maybe_interrupt that calls icount and the helper. I'll give it a bit 
> more testing and re-spin the series.


Don't need to re-spin everything (unless you needed to do some changes in
the patches prior). Just resend patch 27+.


Thanks,


Daniel

> Thanks,
> Matheus K. Ferst
> Instituto de Pesquisas ELDORADO <http://www.eldorado.org.br/>
> Analista de Software
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