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

[John Snow <jsnow@redhat.com>]

On 03/31/2015 04:55 PM, Ed Maste wrote:
> On 23 March 2015 at 12:56, John Snow <jsnow@redhat.com> 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 <jsnow@redhat.com>
>> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
>> Tested-by: Andreas Färber <afaerber@suse.de>
>> Message-id: 1426811056-2202-5-git-send-email-jsnow@redhat.com
>> ---
>>   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.