On Fri, 10 Aug 2018, Joe Perches wrote: > On Fri, 2018-08-10 at 14:12 -0500, Jeff Lien wrote: > > This patch provides a performance improvement for the CRC16 calculations done in read/write > > workloads using the T10 Type 1/2/3 guard field. For example, today with sequential write > > workloads (one thread/CPU of IO) we consume 100% of the CPU because of the CRC16 computation > > bottleneck. Today's block devices are considerably faster, but the CRC16 calculation prevents > > folks from utilizing the throughput of such devices. To speed up this calculation and expose > > the block device throughput, we slice the old single byte for loop into a 16 byte for loop, > > with a larger CRC table to match. The result has shown 5x performance improvements on various > > big endian and little endian systems running the 4.18.0 kernel version. > > Thanks. > > This seems a sensible tradeoff for the 4k text size increase. More like 7.5KB. Would be best if this was configurable so the small version remained available. Nicolas
