Re: [rfc 03/45] Generic CPU operations: Core piece

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

* Christoph Lameter (clameter@sgi.com) wrote:
> On Mon, 19 Nov 2007, Mathieu Desnoyers wrote:
> 
> > 
> > Very interesting patch! I did not expect we could mix local atomic ops
> > with per CPU offsets in an atomic manner.. brilliant :)
> > 
> > Some nitpicking follows...
> 
> Well this is a draft so I was not that thorough. The beast is getting too 
> big. It would be good if I could get the first patches merged that just 
> deal with the two allocators and then gradually work the rest.
> 
> > I think you could use extra () around old, new etc.. ?
> 
> Right.
> 
> > Same here.
> > 
> > > +	(x);					\
> > 
> > () seems unneeded here, since x is local.
> 
> But (x) is returned to the "caller" of the macro so it should be specially 
> marged.
> 

I don't think that it really matters.. the preprocessor already wraps
all the ({ }) in a single statement, doesn't it ?


Grepping for usage of ({ in include/linux shows that the return value is
never surrounded by supplementary ().

> > > + * In that case we can simply disable preemption which
> > > + * may be free if the kernel is compiled without preemption.
> > > + */
> > > +
> > > +#define _CPU_READ(addr)				\
> > > +({						\
> > > +	(__CPU_READ(addr));			\
> > > +})
> > 
> > ({ }) seems to be unneeded here.
> 
> Hmmm.... I wanted a consistent style.
> 

Since checkpatch.pl emits a warning when a one liner if() uses brackets,
I guess compactness of code is preferred to a consistent style.

Just my 2 cents though :)

Mathieu

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68