Re: [PATCH v9 03/12] mm: deferred_init_memmap improvements

[Michal Hocko]

On Tue 03-10-17 12:01:08, Pasha Tatashin wrote:
> Hi Michal,
> 
> Are you OK, if I replace DEFERRED_FREE() macro with a function like this:
> 
> /*
>  * Helper for deferred_init_range, free the given range, and reset the
>  * counters
>  */
> static inline unsigned long __def_free(unsigned long *nr_free,
>                                        unsigned long *free_base_pfn,
>                                        struct page **page)
> {
>         unsigned long nr = *nr_free;
> 
>         deferred_free_range(*free_base_pfn, nr);
>         *free_base_pfn = 0;
>         *nr_free = 0;
>         *page = NULL;
> 
>         return nr;
> }
> 
> Since it is inline, and we operate with non-volatile counters, compiler will
> be smart enough to remove all the unnecessary de-references. As a plus, we
> won't be adding any new branches, and the code is still going to stay
> compact.

OK. It is a bit clunky but we are holding too much state there. I
haven't checked whether that can be simplified but this can be always
done later.
-- 
Michal Hocko
SUSE Labs