The translation is needed to avoid returning a negative number from a successful syscall, and this requirement doesn't apply to setpriority. See the implementation of getpriority in kernel/sys.c. Signed-off-by: Theodore Dubois <tbodt@xxxxxxxxxx> --- man2/getpriority.2 | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git man2/getpriority.2 man2/getpriority.2 index 3e1be3e6c..24c1b7f11 100644 --- man2/getpriority.2 +++ man2/getpriority.2 @@ -206,20 +206,11 @@ All BSD-like systems (SunOS 4.1.3, Ultrix 4.2, manner as Linux 2.6.12 and later. .\" .SS C library/kernel differences -Within the kernel, nice values are actually represented -using the range 40..1 -(since negative numbers are error codes) and these are the values -employed by the -.BR setpriority () -and -.BR getpriority () -system calls. -The glibc wrapper functions for these system calls handle the -translations between the user-land and kernel representations -of the nice value according to the formula +The getpriority system call returns nice values translated to the range 40..1, +since a negative return value would be interpreted as an error. +The glibc wrapper function for getpriority translates the value back according to the formula .IR "unice\ =\ 20\ \-\ knice" . -(Thus, the kernel's 40..1 range corresponds to the -range \-20..19 as seen by user space.) +(Thus, the 40..1 range returned by the kernel corresponds to the range \-20..19 as seen by user space.) .SH BUGS According to POSIX, the nice value is a per-process setting. However, under the current Linux/NPTL implementation of POSIX threads, -- 2.36.0.512.ge40c2bad7a-goog
