Re: A quick fio test (was Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3)

Suparna Bhattacharya
2007-02-26T14:07:47Z

On Mon, Feb 26, 2007 at 02:57:36PM +0100, Jens Axboe wrote:
>
> Some more results, using a larger number of processes and io depths. A
> repeat of the tests from friday, with added depth 20000 for syslet and
> libaio:
>
> Engine Depth Processes Bw (MiB/sec)
> ----------------------------------------------------
> libaio 1 1 602
> syslet 1 1 759
> sync 1 1 776
> libaio 32 1 832
> syslet 32 1 898
> libaio 20000 1 581
> syslet 20000 1 609
>
> syslet still on top. Measuring O_DIRECT reads (of 4kb size) on ramfs
> with 100 processes each with a depth of 200, reading a per-process
> private file of 10mb (need to fit in my ram...) 10 times each. IOW,
> doing 10,000MiB of IO in total:

But, why ramfs ? Don't we want to exercise the case where O_DIRECT actually
blocks ? Or am I missing something here ?

Regards
Suparna

>
> Engine Depth Processes Bw (MiB/sec)
> ----------------------------------------------------
> libaio 200 100 1488
> syslet 200 100 1714
>
> Results are stable to within approx +/- 10MiB/sec. The syslet case
> completes a whole second faster than libaio (~6 vs ~7 seconds). Testing
> was done with fio HEAD eb7c8ae27bc301b77490b3586dd5ccab7c95880a, and it
> uses the v4 patch series.
>
> Engine Depth Processes Bw (MiB/sec)
> ----------------------------------------------------
> libaio 200 100 1488
> syslet 200 100 1714
> sync 200 100 1843
>
> --
> Jens Axboe

--
Suparna Bhattacharya (suparna@in.ibm.com)
Linux Technology Center
IBM Software Lab, India