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

Jens Axboe
2007-02-23T12:53:01Z

On Wed, Feb 21 2007, Ingo Molnar wrote:
> this is the v3 release of the syslet/threadlet subsystem:
>
> http://redhat.com/~mingo/syslet-patches/

[snip]

Ingo, some testing of the experimental syslet queueing stuff, in the
syslet-testing branch of fio.

Fio job file:

[global]
bs=8k
size=1g
direct=0
ioengine=syslet-rw
iodepth=32
rw=read

[file]
filename=/ramfs/testfile

Only changes between runs was changing ioengine and iodepth as indicated
in the table below.

Results:

Engine Depth Bw (MiB/sec)
--------------------------------------------
libaio 1 441
syslet 1 574
sync 1 589
libaio 32 613
syslet 32 681

Results are stable to within +/- 1MiB/sec. So you can see that syslet
are still a bit slower than sync for depth 1, but beats the pants off
libaio for equal depths. Note that this is buffered IO, I'll be out for
the weekend, but I'll hack some direct IO testing up next week to
compare "real" queuing.

Just a quick microbenchmark to gauge current overhead...

--
Jens Axboe