おたすけマンっす、あなたのさがひものは、ここっすかぁ〜。
http://www-124.ibm.com/developerworks/oss/pthreads/

Next Generation POSIX Threading

The goal of this project is to attempt to solve the problems associated with the use of the pthreads library on
Linux. It will add M:N threading capability and improve significantly on the POSIX compliance of pthreads on
Linux. This will allow significant performance improvements for all applications that make use of the pthreads
library, particularly on SMP machines. It will also enable Linux to provide threading services that are more in
line with the capabilities of the commerical Unix operating system such as IBM AIX and SGI IRIX.