| Date | Wed, 4 Mar 2015 12:48:54 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [PATCHv4 03/24] mm: avoid PG_locked on tail pages |
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On Wed, 4 Mar 2015, Kirill A. Shutemov wrote:
> index c851ff92d5b3..58b98bced299 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -207,7 +207,8 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; } > > struct page; /* forward declaration */ > > -TESTPAGEFLAG(Locked, locked) > +#define PageLocked(page) test_bit(PG_locked, &compound_head(page)->flags) > + > PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
Hmmm... Now one of the pageflag functions operates on the head page unlike the other pageflag functions that only operate on the flag indicated.
Given that pageflags provide a way to implement checks for head / tail pages this seems to be a bad idea.
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