On Tue, 2004-08-31 at 03:47, Hiroyuki KAMEZAWA wrote:

"Does a page's buddy page exist or not ?" is checked by following.
------------------------
if ((address of buddy is smaller than that of page) &&
    (page->flags & PG_buddyend))
    this page has no buddy in this order.
------------------------

What about the top-of-the-zone buddyend pages?  Are those covered
elsewhere?

+static inline int page_is_buddy(struct page *page, int order)
+{
+	if (PagePrivate(page) &&
+	    (page_order(page) == order) &&
+	    !(page->flags & (1 << PG_reserved)) &&

Please use a macro.

 	if (order)
 		destroy_compound_page(page, order);
+
 	mask = (~0UL) << order;
 	page_idx = page - base;

Repeat after me: No whitespace changes.  No whitespace changes.  No
whitespace changes.

-- Dave

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