On 03/14/2014 01:45 PM, Matthew Eaton wrote:
>> Interesting, it would make sense to simply not scramble if the compression
>> settings are set. That is what happens with refill_buffers right now, it has
>> precedence over the scrambling. Or if you give a buffer pattern, that also
>> disables the scrambling. I'll add the same for the compression settings.
>>
>> http://git.kernel.dk/?p=fio.git;a=commit;h=0574c885b82aea0332ab5fa35af84db0f3946726
>>
>> Care to give it a test spin, just to be on the safe side?
>>
>> --
>> Jens Axboe
>>
>
> Hey Jens,
>
> According to my test results below it worked for
> buffer_compress_percentage, but not zero_buffers.  Also, it looks like
> buffer_compress_percentage=0 is broken, unless =0 means disabling that
> option altogether.
>
> fio-2.1.6.1-11-g0574
>
> buffer_compress_percentage=100
> iops=83436
>
> buffer_compress_percentage=50
> iops=78625
>
> buffer_compress_percentage=1
> iops=52751
>
> buffer_compress_percentage=0
> iops=69433
>
> zero_buffers
> iops=69470
>
> scramble_buffers=0
> zero_buffers
> iops=83369
>

Doh yes, we can't use that as an enabled flag. Can you apply this on top 
of current git and see if it works? Untested...

-- 
Jens Axboe