Re: [PATCH] sched/clock: cleanup, remove wrap_{max|min}().

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

On 05/07/2014 09:55 PM, Peter Zijlstra wrote:
> On Wed, May 07, 2014 at 08:48:58PM +0900, Dongsheng Yang wrote:
>> I am not sure why we need the wrap_{max|min}() in kernel/sched/clock.c.
>> But I checked the implementation of max() and min() in linux/kernel.h, I think
>> we can reuse them here rather than introduce a new function named
>> wrap_{max|min}().
> wrap is a good hint there.. they're supposed to deal with the clock
> wrapping. Of course 2^64 ns is a rather long time (~584 years in fact),
> but that doesn't mean we shouldn't care.
>
> And no, min/max don't do the right thing.

IMMO,  max() in kernel.h is checking and returning the u64 with typeof() if
we are passing a u64 parameter to max(). And I checked current callers 
of wrap_max(),
they are all passing parameters of u64 type. So I think max/min works 
well at
the place of wrap_max/min().

Maybe I am missing something here, please correct me if I understand it 
incorrectly.

Thanx