On 10/17/18 12:32 PM, Sitsofe Wheeler wrote:
> On Wed, 17 Oct 2018 at 13:31, Changyu <feng_changyu@xxxxxxx> wrote:
>>
>> Hi,
>>
>> I set "dedupe_percentage " to let FIO generate some duplicated data. I also want read these data back and verify it.
>> But, there is no duplicated data after setting "verify" parameter.
>>
>> checking the source code, I found that function do_io in file backend.c fill the buffer twice. the source code is as below.
>>
>> do_io()
>> {
>> io_u = get_io_u(td);
>> .....
>> if (io_u->ddir == DDIR_WRITE && td->flags & TD_F_DO_VERIFY)
>> populate_verify_io_u(td, io_u);
>> }
>>
>> In function get_io_u, the buffer is filled with data as the "dedupe_percentage " specified.
>> In function populate_verify_io_u, the buffer is refilled with random data. So, there would be no duplicated data.
>>
>> Is this a bug?
>
> If it's not (and I'd say it is) then the current behaviour needs to it
> needs to print a "conflicting options" error rather than silently not
> doing what was asked. Someone else has reported something similar over
> on https://github.com/axboe/fio/issues/449 ...
They should definitely be using the same fill methods.
--
Jens Axboe
