Re: comparison of the AF_ALG interface with the /dev/crypto

From: Phil Sutter
Date: Thu Sep 01 2011 - 11:09:32 EST

Herbert,

On Thu, Sep 01, 2011 at 10:14:45PM +0800, Herbert Xu wrote:
> Phil Sutter <phil@xxxxxx> wrote:
> >
> > chunksize af_alg cryptodev (100 * cryptodev / af_alg)
> > --------------------------------------------------------------------------
> > 512 4.169 MB/s 7.113 MB/s 171 %
> > 1024 7.904 MB/s 12.957 MB/s 164 %
> > 2048 13.163 MB/s 19.683 MB/s 150 %
> > 4096 20.218 MB/s 26.960 MB/s 133 %
> > 8192 27.539 MB/s 34.373 MB/s 125 %
> > 16384 33.730 MB/s 39.997 MB/s 119 %
> > 32768 37.399 MB/s 42.727 MB/s 114 %
> > 65536 40.004 MB/s 44.660 MB/s 112 %
>
> Are you maxing out your submission CPU? If not then you're testing
> the latency of the interface, as opposed to the throughput.

Good point. So in order to also test the throughput, I've put my OpenRD
under load:

| stress -c 2 -i 2 -m 2 --vm-bytes 64MB

and ran the tests again:

chunksize af_alg cryptodev (100 * cryptodev / af_alg)
--------------------------------------------------------------------------
512 0.618 MB/s 1.14 MB/s 184 %
1024 1.258 MB/s 2.28 MB/s 181 %
2048 2.453 MB/s 4.39 MB/s 179 %
4096 4.540 MB/s 7.76 MB/s 171 %
8192 7.981 MB/s 11.67 MB/s 146 %
16384 12.543 MB/s 14.08 MB/s 112 %
32768 13.139 MB/s 14.46 MB/s 110 %
65536 14.254 MB/s 15.55 MB/s 109 %

So that means cryptodev-linux is superior in throughput as well as
latency, right? Or is it the lower latency of the interface causing the
higher throughput?

Greetings, Phil
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/