On 03/31/2014 11:09 AM, Christian Lamparter wrote: > Hello, > > On Sunday, March 30, 2014 09:40:24 PM Ben Greear wrote: >> Due to hardware/firmware limitations, it does not appear possible to >> have a wifi NIC do hardware decrypt when using multiple stations on a single >> NIC (and have both stations connected to the same AP). >> >> This just happens to be one of my favourite things to do, and it kills >> performance compared to normal 'Open' throughput. >> >> I am curious if anyone knows of any way to accelerate rx-decrypt, perhaps by >> using a specialized hardware board or maybe a feature of certain CPUs? > > You could check if your CPU (bios and kernel) have support for AES-NI [0]. > AFAICT mac80211 utilizes the cryptoapi. Therefore anything that supports > the proper crypto bindings can be used to accelerate the encryption and > decryption process to some degree. And it just happens that thanks to > AES-NI parts of math can be efficiently calculated by the CPU. I recently took a look at this again, and the Intel E5 I'm using does use the aesni instructions/driver as far as I can tell. Throughput is still around 500Mbps where open is around 800Mbps. perf top shows this: Samples: 37K of event 'cycles', Event count (approx.): 19360716192 12.01% [kernel] [k] math_state_restore 11.64% [kernel] [k] _aesni_enc1 8.25% [kernel] [k] __save_init_fpu 2.44% [kernel] [k] crypto_xor 1.87% [kernel] [k] irq_fpu_usable 1.30% [kernel] [k] aes_encrypt 0.76% [kernel] [k] __kernel_fpu_end .... Any other magic add-in cards that would somehow just make this all faster w/out having to do any real programming work? :) 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
