Re: mmotm 2009-04-10-02-21 uploaded - forkbombed by work_for_cpu

[Linus Torvalds <torvalds@linux-foundation.org>]

So I applied this (commit 01599fca6758d2cd133e78f87426fc851c9ea725: 
"cpufreq: use smp_call_function_[single|many]() in acpi-cpufreq.c"), but 
just realized - because of a compiler warning - that this looks 
suspicious:

On Mon, 13 Apr 2009, Andrew Morton wrote:
> @@ -283,7 +280,7 @@ static unsigned int get_measured_perf(st
>  	unsigned int perf_percent;
>  	unsigned int retval;
>  
> -	if (!work_on_cpu(cpu, read_measured_perf_ctrs, &readin))
> +	if (smp_call_function_single(cpu, read_measured_perf_ctrs, &cur, 1))
>  		return 0;
>  
>  	cur.aperf.whole = readin.aperf.whole -

How and why did that "read_measured_perf_ctrs, &readin" become 
"read_measured_perf_ctrs, &cur" when the work_on_cpu() was converted to 
"smp_call_function_single()"?

Looks like a bug. But such an odd one that I wonder whether there was some 
thought behind it? Andrew? 

		Linus