Re: [PATCH 7/9] sys: Replace hardcoding of -20 and 19 with MIN_NICE and MAX_NICE.

[Dongsheng Yang <yangds.fnst@cn.fujitsu.com>]

Hi Kees,

  On 02/12/2014 02:27 AM, Kees Cook wrote:
> On Mon, Feb 10, 2014 at 11:34 PM, Dongsheng Yang
> <yangds.fnst@cn.fujitsu.com> wrote:
>> Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
>> cc: Andrew Morton <akpm@linux-foundation.org>
>> cc: Oleg Nesterov <oleg@redhat.com>
>> cc: Robin Holt <holt@sgi.com>
>> cc: Al Viro <viro@zeniv.linux.org.uk>
>> cc: Kees Cook <keescook@chromium.org>
>> cc: "Eric W. Biederman" <ebiederm@xmission.com>
>> cc: Stephen Rothwell <sfr@canb.auug.org.au>
>> cc: Peter Zijlstra <peterz@infradead.org>
>> cc: Ingo Molnar <mingo@kernel.org>
>> ---
>>   kernel/sys.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/kernel/sys.c b/kernel/sys.c
>> index c0a58be..adaeab6 100644
>> --- a/kernel/sys.c
>> +++ b/kernel/sys.c
>> @@ -174,10 +174,10 @@ SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
>>
>>          /* normalize: avoid signed division (rounding problems) */
>>          error = -ESRCH;
>> -       if (niceval < -20)
>> -               niceval = -20;
>> -       if (niceval > 19)
>> -               niceval = 19;
>> +       if (niceval < MIN_NICE)
>> +               niceval = MIN_NICE;
>> +       if (niceval > MAX_NICE)
>> +               niceval = MAX_NICE;
> Good catch! I'm all for using names instead of numeric values,
> however, I wonder if it'd be more readable to use "clamp" instead?
>
> niceval = clamp(niceval, MIN_NICE, MAX_NICE);

Good suggestion! This patch here is just to replace the numeric values with
a name defined in prio.h. So I will send another patch to make it more 
readable
with clamp after the patch set here applied. Is this plan ok to you?

Thanx.
>
> -Kees
>
>>          rcu_read_lock();
>>          read_lock(&tasklist_lock);
>> --
>> 1.8.2.1
>>
>
>