Re: [rfc 03/10] Pageflags: Convert to the use of new macros

[Christoph Lameter <clameter@sgi.com>]

On Mon, 3 Mar 2008, Mel Gorman wrote:

> > +PAGEFLAG(Checked, owner_priv_1)		/* Used by some filesystems */
> > +PAGEFLAG(Pinned, owner_priv_1)		/* Xen pinned pagetable */
> 
> This is what I was on about earlier with some flag comments being in a
> separate place. Someone grepping for PG_pinned to see what it is for
> would have a bad day.

These aliases seem to be not a good thing. PG_pinned etc are never used. 
Greeping for SetPagePinned etc may be better.

> > +#ifdef CONFIG_HIGHMEM
> > +#define PageHighMem(page)	is_highmem(page_zone(page))
> > +#else
> > +#define PageHighMem(page)	0 /* needed to optimize away at compile time */
> > +#endif
> > +
> 
> Seems to be a tiny inconsistency here. PageSwapCache below is a static
> inline returning 0 that you fixed up as part of the shuffling where as
> PageHighMem is #defined to 0. Care to fix it up too?

Ok.

> > -#define SetPagePrivate(page)	set_bit(PG_private, &(page)->flags)
> > -#define ClearPagePrivate(page)	clear_bit(PG_private, &(page)->flags)
> > -#define PagePrivate(page)	test_bit(PG_private, &(page)->flags)
> > -#define __SetPagePrivate(page)  __set_bit(PG_private, &(page)->flags)
> > -#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
> > +static inline void set_page_writeback(struct page *page)
> > +{
> > +	test_set_page_writeback(page);
> > +}
> 
> It's been around for ages and unrelated to your patch series but it
> looks odd that set_page_writeback() is simply a function alias that
> ignores return values :/

Yes its strange. Is there a set_page_writeback function?