Hi , The performance will depend on the time taken for calculating the hash1 and hash2 values for each lookup.
Can i know which hash functions are used to calculate the hash values for each incoming key. We use CRC32 which uses xxhash i guess. I could not find the implementation of the hash functions. Thanks, Pragash Vijayaragavan Grad Student at Rochester Institute of Technology email : pxv3...@rit.edu ph : 585 764 4662 On Wed, Aug 23, 2017 at 2:28 PM, Dumitrescu, Cristian < cristian.dumitre...@intel.com> wrote: > > > > -----Original Message----- > > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Pragash > > Vijayaragavan > > Sent: Wednesday, August 23, 2017 3:16 PM > > To: dev@dpdk.org > > Cc: Minseok Kwon <mxk...@rit.edu> > > Subject: [dpdk-dev] cuckoo hash in dpdk > > > > Hi, > > > > I got the chance to look at the cuckoo hash used in dpdk and have a > query. > > > > would using division and modulo operations be slower than bitwise > > operations on RTE_HASH_BUCKET_ENTRIES, specially since > > RTE_HASH_BUCKET_ENTRIES is a power of 2. > > For example, to do a modulo we can do a "AND" operation on > > (RTE_HASH_BUCKET_ENTRIES - 1), which might be faster. We did a cuckoo > > filter for VPP and doing this gave a slight improvement in speed. > > Is there any particular reason its done this way. > > > > Sorry if i am being wrong in any way, i was just curious. > > > > Thanks, > > > > Pragash Vijayaragavan > > Grad Student at Rochester Institute of Technology > > email : pxv3...@rit.edu > > ph : 585 764 4662 > > Bitwise AND typically takes 1 cycle on any CPU, while modulo takes dozens > of cycles. >
