Re: [PATCH] getpriority: Only getpriority translation the priority values

[Alejandro Colomar <alx.manpages@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 <tbodt@google.com>
> 
> 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:

<https://lore.kernel.org/linux-man/809c40c4-068b-8296-57d9-024e6623362d@gmail.com/T/#u>

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/