On 29 March 2015 at 16:07, Andy Polyakov <appro@xxxxxxxxxxx> wrote: >> This updates the SHA-512 NEON module with the faster and more >> versatile implementation from the OpenSSL project. It consists >> of both a NEON and a generic ASM version of the core SHA-512 >> transform, where the NEON version reverts to the ASM version >> when invoked in non-process context. >> >> Performance relative to the generic implementation (measured >> using tcrypt.ko mode=306 sec=1 running on a Cortex-A57 under >> KVM): >> >> input size block size asm neon old neon >> >> 8192 8192 1.51 3.51 2.69 > > One should keep in mind that improvement coefficients vary greatly from > platform to platform. Normally you *should* observe higher coefficients > in asm column and *can* observe smaller differences between "neon" and > "old neon". BTW, 1.51 is unexpectedly low, I wonder which compiler > version stands for 1.0? This was Linaro GCC 4.9 > Nor can I replicate difference between "neon" > and "old neon", I get smaller difference, 17%, on Cortex-A57. Well, I'm > comparing in user-land, but it shouldn't be that significant at large > blocks... > That is a bit surprising, indeed. The primary difference is that this executes under a 32-bit kernel, whereas your testing uses 32-bit OpenSSL under a 64-bit kernel in 32-bit compatibility mode. I can't really explain how that should make a difference at all, but it's worth to be noted. >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> >> --- >> >> This should get the same treatment as Sami's sha56 version: I would like >> to wait until the OpenSSL source file hits the upstream repository so that >> I can refer to its sha1 hash in the commit log. > > Update is committed as > http://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=b1a5d1c652086257930a1f62ae51c9cdee654b2c. > Note that the file I've initially sent privately was a little bit off. > Sorry about that. But that little bit is just a commentary update that > adds performance result for Cortex-A15. So that kernel patch as > originally posted is 100% functionally equivalent. > Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
