Re: [Qemu-devel] [PATCH 4/4] ahci-test: improve rw buffer patterns

[John Snow]

On 03/31/2015 04:55 PM, Ed Maste wrote:
> On 23 March 2015 at 12:56, John Snow <address@hidden> wrote:
> > My pattern was cyclical every 256 bytes, so it missed a fairly obvious
> > failure case. Add some rand() pepper into the test pattern, and for large
> > patterns that exceed 256 sectors, start writing an ID per-sector so that
> > we never generate identical sector patterns.
> >
> > Signed-off-by: John Snow <address@hidden>
> > Reviewed-by: Stefan Hajnoczi <address@hidden>
> > Tested-by: Andreas Färber <address@hidden>
> > Message-id: address@hidden
> > ---
> >   tests/ahci-test.c | 36 ++++++++++++++++++++++++++++--------
> >   1 file changed, 28 insertions(+), 8 deletions(-)
>
> As of the introduction of this test the test suite fails on FreeBSD,
> with 6 errors of the form:
>
> ERROR:tests/ahci-test.c:790:ahci_test_io_rw_simple: assertion failed
> (memcmp(tx, rx, bufsize) == 0): (0xffffffffffffffff == 0x00000000)
> GTester: last random seed: R02S76f68c4cfb2d54af66de227ed44fd54a
>
> I haven't yet done any investigation beyond bisecting.

which test case does it fail under? io_rw_simple is shared by a number 
of different tests.

I suspect deeply that this test pattern has just unearthed an existing 
problem.