[PATCH v9 03/12] mm: deferred_init_memmap improvements

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