On Fri, Apr 20 2007, Christoph Lameter wrote:
> On Fri, 20 Apr 2007, Jens Axboe wrote:
>
> > This works fine as long as you are in the submitter context, but once
> > you pass the into the block layer, we don't have any way to find the
> > address space (at least we don't want to). Would something like this be
> > workable, name withstanding:
> >
> > static unsigned long page_size(struct page *page)
> > {
> > struct address_space *mapping;
> > int order = 0;
> >
> > mapping = page_mapping(page);
> > if (mapping)
> > order = mapping->order;
> >
> > return PAGE_CACHE_SIZE << order;
> > }
>
> There is much simpler solution (possible with mm)
>
> PAGE_SIZE << compound_order(page)
>
> compound_order will return 0 for a non compound page.
Ah perfect, much easier. I'll spin a patchset for the block bits.
--
Jens Axboe
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