On 03/07/2016 02:02 PM, Andrey Kuzmin wrote:
On Mon, Mar 7, 2016 at 11:46 PM, Jeff Furlong <jeff.furlong@xxxxxxxx> wrote:
Thanks for the suggestions and patches. Using the latest fio version, the JESD219 workload is possible:
Nice.
# fio -version
fio-2.6-27-gd283
# fio --name=JESD219 --ioengine=libaio --direct=1 --rw=randrw --norandommap --randrepeat=0 --rwmixread=40 --rwmixwrite=60 --iodepth=256 --size=100% --numjobs=4 --bssplit=512/4:1024/1:1536/1:2048/1:2560/1:3072/1:3584/1:4k/67:8k/10:16k/7:32k/3:64k/3 --random_distribution=zoned:50/5:30/15:20/80 --overwrite=1 --filename=/dev/nvme0n1 --group_reporting --runtime=5m --time_based --output=JESD219
A quick statistical analysis of the results shows:
Found 20380582 IOs
Found 39.9903152913% reads
Found 60.0096847087% writes
Found 4.00492979052% 512
Found 1.00495658073% 1024
Found 1.00079575745% 1536
Found 1.00046701316% 2048
Found 0.998764412125% 2560
Found 0.998043137335% 3072
Found 0.999520033334% 3584
Found 67.0145778958% 4096
Found 9.98662844859% 8192
Found 6.99898560306% 16384
Found 2.99961993235% 32768
Found 2.99271139558% 65536
Found 49.9895734086% 0-5%
Found 30.0126463513% 5-20%%
Found 19.99778024% 20-100%
It hardly matters, but is still somewhat surprising to see that both
bs and zone split percentage are accurate only up to 5x10^-3.
So I did the math on these, an fio is on (or really close) to the
expected deviation for random outcomes.
The first two of the block sizes (didn't check more):
> Found 4.00492979052% 512
3.99387% to 4.00612% would be in the range.
> Found 1.00495658073% 1024
0.9938778% to 1.00612% would be in the range.
For the access location:
> Found 49.9895734086% 0-5%
49.98955% to 50.01044% would be in the range.
> Found 30.0126463513% 5-20%%
29.98955% to 30.01044% would be in the range.
> Found 19.99778024% 20-100%
19.98955% to 20.01044% would be in the range.
So while the deviations from the specified does seem larger than
intuition would lead you to believe, it's actually really close. I think
we can call this one closed.
--
Jens Axboe
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