Re: [PATCH] slab: cleanup kmem_getpages

[Christoph Hellwig <hch@lst.de>]

On Wed, Apr 19, 2006 at 09:20:00AM +1000, David Chinner wrote:
> On Fri, Apr 14, 2006 at 08:36:18PM +0200, Christoph Hellwig wrote:
> > The last ifdef addition hit the ugliness treshold on this functions, so:
> > 
> >  - rename the varibale i to nr_pages so it's somewhat descriptive
> >  - remove the addr variable and do the page_address call at the very end
> >  - instead of ifdef'ing the whole alloc_pages_node call just make the
> >    __GFP_COMP addition to flags conditional
> >  - rewrite the __GFP_COMP comment to make sense
> ....
> > +	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
> >  	if (!page)
> >  		return NULL;
> > -	addr = page_address(page);
> .....
> > +	while (nr_pages--) {
> >  		__SetPageSlab(page);
> >  		page++;
> >  	}
> > -	return addr;
> > +	return page_address(page);
> 
> I think that's a bug - you return the address of the page after the
> allocation, not the first page of the allocation.

You're right.  I wonder why this didn't show up in my testing.  Looks
like slab will never allocate any high-order pages if your page size
is big enough..

Andrew, please drop this for now.  I'll redo it without that bit once
I'll get some time.

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