17.11.2014 17:31, Neil Horman ?????: > On Sun, Nov 16, 2014 at 11:59:16PM +0600, Yerden Zhumabekov wrote: >> This is a rework of my previous patches improving performance of >> rte_hash_crc. In addition, this revision brings a fallback mechanism to >> ensure that CRC32 hash is calculated regardless of hardware support from CPU >> (i.e. SSE4.2 intrinsics). >> >> Summary of changes: >> * added CRC32 software implementation, which is used as a fallback in case >> SSE4.2 is not available, or if SSE4.2 is intentionally disabled. >> * added rte_hash_crc_set_alg() function to control availability of SSE4.2. >> * added rte_hash_crc_8byte() function to calculate CRC32 on 8-byte operand. >> * reworked rte_hash_crc() function which leverages both versions of CRC32 >> hash calculation functions with 4 and 8-byte operands. >> >> Patches were tested on machines either with and without SSE4.2 support. >> Software implementation seems to be about 15 times slower than >> SSE4.2-enabled one. Of course, they return identical results. >> >> Yerden Zhumabekov (4): >> hash: add software CRC32 implementation >> hash: add new rte_hash_crc_8byte call >> hash: add fallback to software CRC32 implementation >> hash: rte_hash_crc() slices data into 8-byte pieces >> >> lib/librte_hash/rte_hash_crc.h | 212 >> ++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 202 insertions(+), 10 deletions(-) >> >> -- >> 1.7.9.5 >> >> > Functionally this all looks great, but I think you want to add a 5th patch to > the series in which you remove the ifdef SSE4.2 bits from test_hash_perf, > since > this makes rte_hash_crc usable in all cases. Not sure if you would rather > just > ditch rte_hash_jhash alltogether, or make testing it a command line runtime > option
Meanwhile, I've borrowed some Intel's code (BSD licensed) for CRC32 sw algorithm, it runs 4 times faster sacrificing memory (2K) for additional lookup tables. I'd like to include it as well. As for test_hash_perf, I'll look at it. Should I just send new series over as 'v3'? Any approval/disapproval for the current series? -- Sincerely, Yerden Zhumabekov State Technical Service Astana, KZ
