Re: OOPS: 2.6.16-rc6 cpufreq_conservative

[Linus Torvalds <torvalds@osdl.org>]

On Mon, 20 Mar 2006, Willy Tarreau wrote:
> 
> Now, does removing the macro completely change the output code ?
> I think that if something written like this produces the same
> code, it would be easier to read :
> 
> #define for_each_cpu_mask(cpu, mask)			\
> 	for ((cpu) = 0; (cpu) < NR_CPUS; (cpu)++) {	\
> 		unsigned long __bits = (mask).bits[0] >> (cpu); \
> 		if (!__bits)				\
> 			break;				\
> 		if (!__bits & 1)			\
> 			continue;			\
> 		else

Absolutely, but now it has a dangling "{" that didn't get closed. So the 
above would definitely be more readable, it just doesn't actually work.

Unless you'd do the "end_for_each_cpu" define (to close the statement), 
and update the 300+ places that use this. Which might well be worth it.

So the subtle "break from the middle of a statement expression" was just a 
rather hacky way to avoid having to change all the users of this macro.

			Linus
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