[PATCH] hugepage fixes

From: William Lee Irwin III <wli@holomorphy.com>

mm/hugetlb.c is putting the destructor in head->lru.prev not head[1].mapping;
fix below along with nuking huge_page_release(), which simply duplicates
put_page().

arch/i386/mm/hugetlbpage.c

@@ -220,7 +220,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma,
 		if (pte_none(pte))
 			continue;
 		page = pte_page(pte);
-		huge_page_release(page);
+		put_page(page);
 	}
 	mm->rss -= (end - start) >> PAGE_SHIFT;
 	flush_tlb_range(vma, start, end);

arch/ia64/mm/hugetlbpage.c

@@ -248,7 +248,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsig
 		if (pte_none(*pte))
 			continue;
 		page = pte_page(*pte);
-		huge_page_release(page);
+		put_page(page);
 		pte_clear(pte);
 	}
 	mm->rss -= (end - start) >> PAGE_SHIFT;

arch/ppc64/mm/hugetlbpage.c

@@ -394,7 +394,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma,
 			flush_hash_hugepage(mm->context, addr,
 					    pte, local);
 
-		huge_page_release(page);
+		put_page(page);
 	}
 
 	mm->rss -= (end - start) >> PAGE_SHIFT;

arch/sh/mm/hugetlbpage.c

@@ -200,7 +200,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma,
 		if (pte_none(*pte))
 			continue;
 		page = pte_page(*pte);
-		huge_page_release(page);
+		put_page(page);
 		for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 			pte_clear(pte);
 			pte++;

arch/sparc64/mm/hugetlbpage.c

@@ -196,7 +196,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma,
 		if (pte_none(*pte))
 			continue;
 		page = pte_page(*pte);
-		huge_page_release(page);
+		put_page(page);
 		for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 			pte_clear(pte);
 			pte++;

fs/hugetlbfs/inode.c

@@ -142,7 +142,7 @@ void huge_pagevec_release(struct pagevec *pvec)
 	int i;
 
 	for (i = 0; i < pagevec_count(pvec); ++i)
-		huge_page_release(pvec->pages[i]);
+		put_page(pvec->pages[i]);
 
 	pagevec_reinit(pvec);
 }
@@ -152,7 +152,7 @@ void truncate_huge_page(struct page *page)
 	clear_page_dirty(page);
 	ClearPageUptodate(page);
 	remove_from_page_cache(page);
-	huge_page_release(page);
+	put_page(page);
 }
 
 void truncate_hugepages(struct address_space *mapping, loff_t lstart)

include/linux/hugetlb.h

@@ -16,7 +16,6 @@ int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page
 void zap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
 void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long);
 int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
-void huge_page_release(struct page *);
 int hugetlb_report_meminfo(char *);
 int is_hugepage_mem_enough(size_t);
 unsigned long hugetlb_total_pages(void);
@@ -68,7 +67,6 @@ static inline unsigned long hugetlb_total_pages(void)
 #define hugetlb_prefault(mapping, vma)		({ BUG(); 0; })
 #define zap_hugepage_range(vma, start, len)	BUG()
 #define unmap_hugepage_range(vma, start, end)	BUG()
-#define huge_page_release(page)			BUG()
 #define is_hugepage_mem_enough(size)		0
 #define hugetlb_report_meminfo(buf)		0
 #define mark_mm_hugetlb(mm, vma)		do { } while (0)

mm/hugetlb.c

@@ -78,20 +78,12 @@ struct page *alloc_huge_page(void)
 	free_huge_pages--;
 	spin_unlock(&hugetlb_lock);
 	set_page_count(page, 1);
-	page->lru.prev = (void *)free_huge_page;
+	page[1].mapping = (void *)free_huge_page;
 	for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
 		clear_highpage(&page[i]);
 	return page;
 }
 
-void huge_page_release(struct page *page)
-{
-	if (!put_page_testzero(page))
-		return;
-
-	free_huge_page(page);
-}
-
 static int __init hugetlb_init(void)
 {
 	unsigned long i;