Since kernel 1.3.43, Linux has the range \-20..19.
On some other systems, the range of nice values is \-20..20.
+Including
+.I <sys/time.h>
+is not required these days, but increases portability.
+(Indeed,
+.I <sys/resource.h>
+defines the
+.I rusage
+structure with fields of type
+.I struct timeval
+defined in
+.IR <sys/time.h> .)
+.\"
+.SS C library/kernel ABI differences
Within the kernel, nice values are actually represented
using the corresponding range 40..1
(since negative numbers are error codes) and these are the values
translations between the user-land and kernel representations
of the nice value according to the formula
.IR "unice\ =\ 20\ \-\ knice" .
-.LP
-Including
-.I <sys/time.h>
-is not required these days, but increases portability.
-(Indeed,
-.I <sys/resource.h>
-defines the
-.I rusage
-structure with fields of type
-.I struct timeval
-defined in
-.IR <sys/time.h> .)
.SH BUGS
According to POSIX, the nice value is a per-process setting.
However, under the current Linux/NPTL implementation of POSIX threads,