Re: [RFC][PATCH] kernel.h: Add generic roundup_64() macro

[Nikolay Borisov]

On 24.05.19 Ð. 18:26 Ñ., Steven Rostedt wrote:
> On Fri, 24 May 2019 16:11:14 +0100
> Roger Willcocks <roger@xxxxxxxxxxxxxxxx> wrote:
> 
>> On 23/05/2019 16:27, Steven Rostedt wrote:
>>>
>>> I haven't yet tested this, but what about something like the following:
>>>
>>> ...perhaps forget about the constant check, and just force
>>> the power of two check:
>>>
>>> 							\
>>> 	if (!(__y & (__y >> 1))) {			\
>>> 		__x = round_up(x, y);			\
>>> 	} else {					\  
>>
>> You probably want
>>
>>  ÂÂÂÂÂÂÂÂÂÂ if (!(__y & (__y - 1))
>>
>> --
> 
> Yes I do. I corrected it in my next email.
> 
>  http://lkml.kernel.org/r/20190523133648.591f9e78@xxxxxxxxxxxxxxxxxx

Or perhaps just using is_power_of_2 from include/linux/log2.h ?
> 
>> #define roundup(x, y) (					\
>> {							\
>> 	typeof(y) __y = y;				\
>> 	typeof(x) __x;					\
>> 							\
>> 	if (__y & (__y - 1))				\
>> 		__x = round_up(x, __y);			\
>> 	else						\
>> 		__x = (((x) + (__y - 1)) / __y) * __y;	\
>> 	__x;						\
>> })
> 
> 
> -- Steve
>