Re: [dpdk-dev] [PATCH v2 03/12] crypto/armv8: Add core crypto operations for ARMv8

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-12-07 02:48, Jerin Jacob:
> On Tue, Dec 06, 2016 at 09:29:25PM +0100, Thomas Monjalon wrote:
> > 2016-12-06 18:32, zbigniew.bodek@caviumnetworks.com:
> > > From: Zbigniew Bodek <zbigniew.bodek@caviumnetworks.com>
> > > 
> > > This patch adds core low-level crypto operations
> > > for ARMv8 processors. The assembly code is a base
> > > for an optimized PMD and is currently excluded
> > > from the build.
> > 
> > It's a bit sad that you cannot achieve the same performance with
> > C code and a good compiler.
> > Have you tried it? How much is the difference?
> 
> Like AES-NI on IA side(exposed as separate PMD in dpdk),
> armv8 has special dedicated instructions for crypto operation using SIMD.
> This patch is using the "dedicated" armv8 crypto instructions and SIMD
> operation to achieve better performance.

It does not justify to have all the code in asm.

> We had compared with openssl implementation.Here is the performance
> improvement for chained crypto operations case WRT openssl pmd
> 
> Buffer
> Size(B)   OPS(M)      Throughput(Gbps)
> 64        729 %        742 %
> 128       577 %        592 %
> 256       483 %        476 %
> 512       336 %        351 %
> 768       300 %        286 %
> 1024      263 %        250 %
> 1280      225 %        229 %
> 1536      214 %        213 %
> 1792      186 %        203 %
> 2048      200 %        193 %

OK but what is the performance difference between this asm code
and a C equivalent?