On 08/14/2014 10:09 AM, Ben Greear wrote: > On 08/14/2014 05:39 AM, Christian Lamparter wrote: >> On Tuesday, August 12, 2014 11:34:59 AM Ben Greear wrote: >>> On 08/10/2014 06:44 AM, Christian Lamparter wrote: >>>> On Thursday, August 07, 2014 10:45:01 AM Ben Greear wrote: >>>>> On 08/07/2014 07:05 AM, Christian Lamparter wrote: >>>>>> 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 <greearb@xxxxxxxxxxxxxxx> Candela Technologies Inc http://www.candelatech.com -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
