Re: [PATCH 2/2] make new alloc_pages_exact()

From: Dave Hansen
Date: Fri Apr 08 2011 - 09:19:57 EST


On Fri, 2011-04-08 at 14:28 +0200, Michal Nazarewicz wrote:
> On Thu, 07 Apr 2011 19:21:05 +0200, Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
> wrote:
> > +struct page *__alloc_pages_exact(gfp_t gfp_mask, size_t size)
> > {
> > unsigned int order = get_order(size);
> > - unsigned long addr;
> > + struct page *page;
> > - addr = __get_free_pages(gfp_mask, order);
> > - if (addr) {
> > - unsigned long alloc_end = addr + (PAGE_SIZE << order);
> > - unsigned long used = addr + PAGE_ALIGN(size);
> > + page = alloc_pages(gfp_mask, order);
> > + if (page) {
> > + struct page *alloc_end = page + (1 << order);
> > + struct page *used = page + PAGE_ALIGN(size)/PAGE_SIZE;
> > - split_page(virt_to_page((void *)addr), order);
> > + split_page(page, order);
> > while (used < alloc_end) {
> > - free_page(used);
> > - used += PAGE_SIZE;
> > + __free_page(used);
> > + used++;
> > }
>
> Have you thought about moving this loop to a separate function, ie.
> _free_page_range(start, end)? I'm asking because this loop appears
> in two places and my CMA would also benefit from such a function.

Sounds like a good idea to me. Were you thinking start/end 'struct
page's as arguments?

-- Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/