Re: [PATCH] Avoid panic when adjusting sedf parameters

[Keir Fraser <keir.xen@gmail.com>]

On 17/11/2011 13:30, "Jan Beulich" <JBeulich@suse.com> wrote:

> which would now associate the else with the wrong (inner) if. One
> possible solution that comes to mind would be
> 
> #define for_each_domain_in_cpupool(_d,_c) \
>     for_each_domain_in_cpupool (_d) \
>         if ((_d)->cpupool != (_c)) \
>             continue; \
>         else
> 
> but I think I had seen a more clever solution to this problem, but cannot
> remember/locate it right now.

Given the gcc ({}) construction, you could do a double-loop:
 for ( (_d) = rcu_dereference(domain_list);     \
       (_d) != NULL;                            \
       ({ while ((_d) = rcu_dereference((_d)->next_in_list != NULL)
             if ((_d)->cpupool == (_c)) break;
          (_d); }) )

A bit ugly. ;-) And I still worry about cpupool locking...

 -- Keir