bitcoin/bitcoin — pull request #2349 by dserrano5 (2013-03-08 19:06:11+00:00)
Title: Accept negative -par values to leave N CPUs free.

Giving negative values to the -par parameter causes bitcoin to run with 1 verification thread. It can be useful to tell bitcoin to use all existing CPUs but leave e.g. 1 of them free for another tasks; this patch allows that by specifying -par=-1.