Hi Theodore,
On 5/11/22 00:08, Theodore Dubois wrote:
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>
Patch applied.
BTW, I had to manually edit the patch.
It's the second time I see this (I can't find the other one), your patch
didn't apply for the following reason: the a/ and b/ prefixes in the
file paths are missing. Did you use git-format-patch(1) to produce the
patch? Can you reproduce this?
I CCd the git mailing list in case they know what's going on.
Thanks,
Alex
---
man2/getpriority.2 | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git man2/getpriority.2 man2/getpriority.2
Should have been:
diff --git a/man2/getpriority.2 b/man2/getpriority.2
index 3e1be3e6c..24c1b7f11 100644
--- man2/getpriority.2
+++ man2/getpriority.2
Should have been:
--- a/man2/getpriority.2
+++ b/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,
--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/
