On 08/14/2014 10:09 AM, Ben Greear wrote:

On 08/14/2014 05:39 AM, Christian Lamparter wrote:

quoted

On Tuesday, August 12, 2014 11:34:59 AM Ben Greear wrote:

quoted

On 08/10/2014 06:44 AM, Christian Lamparter wrote:

quoted

On Thursday, August 07, 2014 10:45:01 AM Ben Greear wrote:

quoted

On 08/07/2014 07:05 AM, Christian Lamparter wrote:

quoted

Or: for every 16 Bytes of payload there is one fpu context save and
restore... ouch!

Any idea if it would work to put the fpu_begin/end a bit higher
and do all those 16 byte chunks in a batch without messing with
the FPU for each chunk?

It sort of works - see sample feature patch for aesni-intel-glue 
(taken from 3.16-wl). Older kernels (like 3.15, 3.14) need:
"crypto: allow blkcipher walks over AEAD data" [0] (and maybe more).

The FPU save/restore overhead should be gone. Also, if the aesni
instructions can't be used, the implementation will fall back
to the original ccm(aes) code. Calculating the MAC is still much
more expensive than the payload encryption or decryption. However,
I can't see a way of making this more efficient without rewriting
and combining the parts I took from crypto/ccm.c into an several, 
dedicated assembler functions.

Without encryption, I see download rate of around 400 - 420Mbps.

So, your patch looks like a good improvement to me, and I'll be
happy to test further patches if you happen to do those assembler
optimizations you talk about above.

Maybe, that will depend on what the results for: "wpa2, *HW*-crypt,
download, udp" are.

I'll do that test sometime soon and post the results.

I ran that today, and I get about the same throughput with hw-crypt or
sw-crypt (350-355Mbps UDP download goodput).

I still see 400+Mbps with Open authentication.

So, maybe the bottleneck now is elsewhere...

Thanks,
Ben

-- 
Ben Greear [off-list ref]
Candela Technologies Inc  http://www.candelatech.com