malloc, thread and alignment

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

jemmaloc(3) says:
  Allocations are packed tightly together, which can be an issue for multi-
  threaded applications.  If you need to assure that allocations do not
  suffer from cache line sharing, round your allocation requests up to the
  nearest multiple of the cache line size.

Do we are example of how it should be done? I do not know how to discover
cache line size, neither do I know how I can specify alignment based on it.

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost