Things changed a little with:
commit
cd3d8031eb4311e516329aee03c79a08333141f1
Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Fri Mar 12 16:15:36 2010 +0900
Reported-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
.IR "unsigned long\ *" ,
reflecting the fact that the underlying implementation of CPU
sets is a simple bit mask.
+.PP
On success, the raw
.BR sched_getaffinity ()
-system call returns the size (in bytes) of the
+system call returns the number of bytes placed copied into the
+.I mask
+buffer;
+this will be the minimum of
+.I cpusetsize
+and the size (in bytes) of the
.I cpumask_t
data type that is used internally by the kernel to
represent the CPU set bit mask.