Re: [RFC][PATCH 1/4] add jiffies_to_nsecs() helper and fix up size of usecs

[Pavel Machek <pavel@ucw.cz>]

Hi!

> > > +static inline u64 jiffies_to_nsecs(const unsigned long j)
> > > +{
> > > +#if HZ <= NSEC_PER_SEC && !(NSEC_PER_SEC % HZ)
> > > +	return (NSEC_PER_SEC / HZ) * (u64)j;
> > > +#elif HZ > NSEC_PER_SEC && !(HZ % NSEC_PER_SEC)
> > > +	return ((u64)j + (HZ / NSEC_PER_SEC) - 1)/(HZ / NSEC_PER_SEC);
> > > +#else
> > > +	return ((u64)j * NSEC_PER_SEC) / HZ;
> > > +#endif
> > > +}
> > 
> > That might look a little better something like:
> > 
> > static inline u64 jiffies_to_nsecs(const unsigned long __j)
> > {
> > 	u64 j = __j;
> > 
> > 	if (HZ <= NSEC_PER_SEC && !(NSEC_PER_SEC % HZ))
> > 		return (NSEC_PER_SEC / HZ) * j;
> > 	else if (HZ > NSEC_PER_SEC && !(HZ % NSEC_PER_SEC))
> > 		return (j + (HZ / NSEC_PER_SEC) - 1)/(HZ / NSEC_PER_SEC);
> > 	else
> > 		return (j * NSEC_PER_SEC) / HZ;
> > }
> > 
> > Compilers are smart :)
> 
> Well, I was trying to keep it similar to the other conversion functions.
> I guess the compiler can evaluate the conditional full of constants at
> compile-time regardless of whether it is #if or if ().
> 
> I can make these changes if others would like them as well.

Yes, please. And feel free to convert nearby functions, too ;-).
								Pavel
-- 
teflon -- maybe it is a trademark, but it should not be.
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