I am currently have Centos 5.5 which consumes more CPU waiting for Kcrypt process. Later came to know that kcrypt is single threaded and hence consumes one CPU, results in performance degradation.
Does any one really knows/practically experimented multithread of Kcryptd process with any of Kernel versions ?
It's a difficult question, whether it's even feasible to run this kind of encryption on multiple cores.
One workaround has been to make two separate dm-crypt volumes of identical size, then make a single software raid-0 out of them (i.e. striping). Each dm-crypt volume will have its own data path, and performance will be increased.