Re: [Qemu-devel] QEMU postcopy-test failing on ppc64

[Dr. David Alan Gilbert]

* Stefan Hajnoczi (address@hidden) wrote:
> I hit a failure running "make check" on ppc64 for the first time.  Ideas?

Hmm shouldn't happen; cc'ing in lvivier, I've not checked it since Laurent got
the test working on PPC.

> Stefan
> 
> commit 682df581c65ed2c1b9e77093e332214ecaa1ee93
> 
>   GTESTER check-qtest-ppc64
> Memory content inconsistency at 5af4000 first_byte = 1b last_byte = 1a
> current = 7c hit_edge = 1
> Memory content inconsistency at 5af5000 first_byte = 1b last_byte = 7c
> current = 1b hit_edge = 1

The idea is that one byte in every 4k chunk of memory is being incremented
and the loop increments all those bytes once and then loops back to the
start.  So if you pause it at any point and look at memory you should
see two different values in memory, one before the edge that's getting
incremented and one after the edge - and the difference should be
exactly one.  So in this case we're seeing that the start of memory
has the value '1b' and at 5af3000 we have the value 1a (last_byte)
so somewhere between the two is the edge where it's currently incrementing;
then it should stay at 1a until the end of memory - but instead a '7c'
has somehow got in.

My only thought would be to bisect.

Dave

> Memory content inconsistency at 5e59000 first_byte = 1b last_byte = 1b
> current = 1a hit_edge = 1
> **
> ERROR:tests/postcopy-test.c:345:check_guests_ram: 'bad' should be FALSE
> GTester: last random seed: R02S9d79166a1ca7e21940a0f4b0b1255d5b
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK