Re: [patch v4 0/3] aio: implement request batching [more performance numbers]

From: Jeff Moyer
Date: Wed Oct 07 2009 - 08:11:07 EST


Jens Axboe <jens.axboe@xxxxxxxxxx> writes:

> So here's a pretty basic test. It does random reads from a bunch of
> devices, I tested both 4kb and 64kb block sizes. Queue depth used is 32
> for both cases, but note that this test uses a thread per device (so the
> queue depth is 32 per device). Results are averaged over 3 runs.
> slat/clat are the submission and completion latencies, they are in
> microseconds here.
>
> 4kb random reads
>
> kernel sys IOPS slat clat
> ----------------------------------------------------
> 2.6.32-rc3+patch 25.8% 192500 7.9 2606
> 2.6.32-rc3 27.4% 191300 8.4 2612
>
>
>
> 64kb random reads
>
> kernel sys IOPS slat clat
> ----------------------------------------------------
> 2.6.32-rc3+patch 2.5% 24590 9.7 9681
> 2.6.32-rc3 2.5% 24580 9.4 9691
>
> So pretty close, nothing earth shattering here. What the results above
> do not show is that the 4kb test runs very stable with your patch.
> Mainline fluctuates somewhat in the bandwidth, most likely due to the
> varying depth.

OK, good news. Thanks for testing!

Cheers,
Jeff
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