Re: [dm-devel] [PATCH v8 01/16] hashtable: introduce a small and naive hashtable

[Steven Rostedt <rostedt goodmis org>]

On Tue, 2012-10-30 at 20:33 -0400, Sasha Levin wrote:
> On Tue, Oct 30, 2012 at 5:42 PM, Tejun Heo <tj kernel org> wrote:
> > Hello,
> >
> > Just some nitpicks.
> >
> > On Tue, Oct 30, 2012 at 02:45:57PM -0400, Sasha Levin wrote:
> >> +/* Use hash_32 when possible to allow for fast 32bit hashing in 64bit kernels. */
> >> +#define hash_min(val, bits)                                                  \
> >> +({                                                                           \
> >> +     sizeof(val) <= 4 ?                                                      \
> >> +     hash_32(val, bits) :                                                    \
> >> +     hash_long(val, bits);                                                   \
> >> +})
> >
> > Doesn't the above fit in 80 column.  Why is it broken into multiple
> > lines?  Also, you probably want () around at least @val.  In general,
> > it's a good idea to add () around any macro argument to avoid nasty
> > surprises.
> 
> It was broken to multiple lines because it looks nicer that way (IMO).
> 
> If we wrap it with () it's going to go over 80, so it's going to stay
> broken down either way :)

({								      \
	sizeof(val) <= 4 ? hash_32(val, bits) : hash_long(val, bits); \
})

Is the better way to go. We are C programmers, we like to see the ?: on
a single line if possible. The way you have it, looks like three
statements run consecutively.

-- Steve