Re: [PATCH v2 1/2] block: Explicit null-co uses 'read-zeroes=false'

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Vladimir,

On 2/11/21 5:29 PM, Vladimir Sementsov-Ogievskiy wrote:
> 11.02.2021 17:26, Philippe Mathieu-Daudé wrote:
>> We are going to switch the 'null-co' default 'read-zeroes' value
>> from FALSE to TRUE in the next commit. First explicit the FALSE
>> value when it is not set.
>>
>> Suggested-by: Eric Blake <eblake@redhat.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> - Missing: 056 & 155. I couldn't figure out the proper syntax,
>>    any help welcomed...
>> - I'm unsure about 162, this doesn't seem to use the null-co
>>    driver but rather testing global syntax.
>> ---
>>   docs/devel/testing.rst                     | 14 +++++++-------
>>   tests/qtest/fuzz/generic_fuzz_configs.h    | 11 ++++++-----
>>   tests/test-bdrv-drain.c                    | 10 ++++++++--
>>   tests/acceptance/virtio_check_params.py    |  2 +-
>>   tests/perf/block/qcow2/convert-blockstatus |  6 +++---
>>   tests/qemu-iotests/040                     |  2 +-
>>   tests/qemu-iotests/041                     | 12 ++++++++----
>>   tests/qemu-iotests/051                     |  2 +-
>>   tests/qemu-iotests/051.out                 |  2 +-
>>   tests/qemu-iotests/051.pc.out              |  4 ++--
>>   tests/qemu-iotests/087                     |  6 ++++--
>>   tests/qemu-iotests/118                     |  2 +-
>>   tests/qemu-iotests/133                     |  2 +-
>>   tests/qemu-iotests/153                     |  8 ++++----
>>   tests/qemu-iotests/184                     |  2 ++
>>   tests/qemu-iotests/184.out                 | 10 +++++-----
>>   tests/qemu-iotests/218                     |  3 +++
>>   tests/qemu-iotests/224                     |  3 ++-
>>   tests/qemu-iotests/224.out                 |  8 ++++----
>>   tests/qemu-iotests/225                     |  2 +-
>>   tests/qemu-iotests/227                     |  4 ++--
>>   tests/qemu-iotests/227.out                 |  4 ++--
>>   tests/qemu-iotests/228                     |  2 +-
>>   tests/qemu-iotests/235                     |  1 +
>>   tests/qemu-iotests/245                     |  2 +-
>>   tests/qemu-iotests/270                     |  2 +-
>>   tests/qemu-iotests/283                     |  3 ++-
>>   tests/qemu-iotests/283.out                 |  4 ++--
>>   tests/qemu-iotests/299                     |  1 +
>>   tests/qemu-iotests/299.out                 |  2 +-
>>   tests/qemu-iotests/300                     |  4 ++--
> 
> Why do you think these tests will work bad with new default?

As I don't understand the tests, this was the deal with Eric :)

"OK to change default if current default is explicited" then
block maintainers could audit each case and see which one can
safely use read-zeroes=true.

> 
> At least everything under tests/qemu-iotests/ and tests/test-bdrv-drain
> are not about performance
> 
> tests/perf/block/qcow2/convert-blockstatus is OK with new default too.

OK, I'll see who should send these patches on top with Eric & Max.

Thank for your review,

Phil.