From: Alejandro Colomar Date: Sat, 14 May 2022 15:00:14 GMT Subject: Re: [PATCH] getpriority: Only getpriority translation the priority values Message-ID: <76ff060f-a3f2-2e60-5b1a-4a59cf3f3d8c@gmail.com> In-Reply-To: <0fc70bd3-5883-47e4-1814-6ed6c756a400@gmail.com> [CC += nick] On 5/14/22 16:37, Alejandro Colomar wrote: > 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 > > 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 The other one: nick, I finally found it again! > 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/