The compound page logic is using page->lru, and these get will scribbled on
in various places so switch the Compound page logic over to using ->mapping
and ->private.
---
25-akpm/arch/i386/mm/hugetlbpage.c | 1 -
25-akpm/arch/ia64/mm/hugetlbpage.c | 1 -
25-akpm/arch/ppc64/mm/hugetlbpage.c | 1 -
25-akpm/arch/sparc64/mm/hugetlbpage.c | 1 -
25-akpm/include/linux/mm.h | 10 +++++-----
25-akpm/mm/page_alloc.c | 31 ++++++++++++++++---------------
6 files changed, 21 insertions(+), 24 deletions(-)
diff -puN mm/page_alloc.c~compound-pages-stop-using-lru mm/page_alloc.c
--- 25/mm/page_alloc.c~compound-pages-stop-using-lru 2004-03-26 12:36:42.003714088 -0800
+++ 25-akpm/mm/page_alloc.c 2004-03-26 12:36:42.013712568 -0800
@@ -71,13 +71,14 @@ static int bad_range(struct zone *zone,
static void bad_page(const char *function, struct page *page)
{
- printk("Bad page state at %s (in process '%s', page %p)\n", function, current->comm, page);
- printk("flags:0x%08lx mapping:%p mapped:%d count:%d\n",
+ printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
+ function, current->comm, page);
+ printk(KERN_EMERG "flags:0x%08lx mapping:%p mapped:%d count:%d\n",
(unsigned long)page->flags, page->mapping,
page_mapped(page), page_count(page));
- printk("Backtrace:\n");
+ printk(KERN_EMERG "Backtrace:\n");
dump_stack();
- printk("Trying to fix it up, but a reboot is needed\n");
+ printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
page->flags &= ~(1 << PG_private |
1 << PG_locked |
1 << PG_lru |
@@ -99,13 +100,13 @@ static void bad_page(const char *functio
*
* The remaining PAGE_SIZE pages are called "tail pages".
*
- * All pages have PG_compound set. All pages have their lru.next pointing at
+ * All pages have PG_compound set. All pages have their ->private pointing at
* the head page (even the head page has this).
*
- * The head page's lru.prev, if non-zero, holds the address of the compound
- * page's put_page() function.
+ * The first tail page's ->mapping, if non-zero, holds the address of the
+ * compound page's put_page() function.
*
- * The order of the allocation is stored in the first tail page's lru.prev.
+ * The order of the allocation is stored in the first tail page's ->index
* This is only for debug at present. This usage means that zero-order pages
* may not be compound.
*/
@@ -114,13 +115,13 @@ static void prep_compound_page(struct pa
int i;
int nr_pages = 1 << order;
- page->lru.prev = NULL;
- page[1].lru.prev = (void *)order;
+ page[1].mapping = 0;
+ page[1].index = order;
for (i = 0; i < nr_pages; i++) {
struct page *p = page + i;
SetPageCompound(p);
- p->lru.next = (void *)page;
+ p->private = (unsigned long)page;
}
}
@@ -129,7 +130,7 @@ static void destroy_compound_page(struct
int i;
int nr_pages = 1 << order;
- if (page[1].lru.prev != (void *)order)
+ if (page[1].index != order)
bad_page(__FUNCTION__, page);
for (i = 0; i < nr_pages; i++) {
@@ -137,7 +138,7 @@ static void destroy_compound_page(struct
if (!PageCompound(p))
bad_page(__FUNCTION__, page);
- if (p->lru.next != (void *)page)
+ if (p->private != (unsigned long)page)
bad_page(__FUNCTION__, page);
ClearPageCompound(p);
}
@@ -512,14 +513,14 @@ static struct page *buffered_rmqueue(str
spin_lock_irqsave(&zone->lock, flags);
page = __rmqueue(zone, order);
spin_unlock_irqrestore(&zone->lock, flags);
- if (order && page)
- prep_compound_page(page, order);
}
if (page != NULL) {
BUG_ON(bad_range(zone, page));
mod_page_state_zone(zone, pgalloc, 1 << order);
prep_new_page(page, order);
+ if (order)
+ prep_compound_page(page, order);
}
return page;
}
diff -puN include/linux/mm.h~compound-pages-stop-using-lru include/linux/mm.h
--- 25/include/linux/mm.h~compound-pages-stop-using-lru 2004-03-26 12:36:42.004713936 -0800
+++ 25-akpm/include/linux/mm.h 2004-03-26 12:36:42.014712416 -0800
@@ -242,24 +242,24 @@ extern void FASTCALL(__page_cache_releas
static inline int page_count(struct page *p)
{
if (PageCompound(p))
- p = (struct page *)p->lru.next;
+ p = (struct page *)p->private;
return atomic_read(&(p)->count);
}
static inline void get_page(struct page *page)
{
if (PageCompound(page))
- page = (struct page *)page->lru.next;
+ page = (struct page *)page->private;
atomic_inc(&page->count);
}
static inline void put_page(struct page *page)
{
if (PageCompound(page)) {
- page = (struct page *)page->lru.next;
+ page = (struct page *)page->private;
if (put_page_testzero(page)) {
- if (page->lru.prev) { /* destructor? */
- (*(void (*)(struct page *))page->lru.prev)(page);
+ if (page[1].mapping) { /* destructor? */
+ (*(void (*)(struct page *))page[1].mapping)(page);
} else {
__page_cache_release(page);
}
diff -puN arch/i386/mm/hugetlbpage.c~compound-pages-stop-using-lru arch/i386/mm/hugetlbpage.c
--- 25/arch/i386/mm/hugetlbpage.c~compound-pages-stop-using-lru 2004-03-26 12:36:42.005713784 -0800
+++ 25-akpm/arch/i386/mm/hugetlbpage.c 2004-03-26 12:36:42.015712264 -0800
@@ -299,7 +299,6 @@ follow_huge_pmd(struct mm_struct *mm, un
static void free_huge_page(struct page *page)
{
BUG_ON(page_count(page));
- BUG_ON(page->mapping);
INIT_LIST_HEAD(&page->lru);
diff -puN arch/ia64/mm/hugetlbpage.c~compound-pages-stop-using-lru arch/ia64/mm/hugetlbpage.c
--- 25/arch/ia64/mm/hugetlbpage.c~compound-pages-stop-using-lru 2004-03-26 12:36:42.007713480 -0800
+++ 25-akpm/arch/ia64/mm/hugetlbpage.c 2004-03-26 12:36:42.016712112 -0800
@@ -246,7 +246,6 @@ follow_huge_pmd(struct mm_struct *mm, un
void free_huge_page(struct page *page)
{
BUG_ON(page_count(page));
- BUG_ON(page->mapping);
INIT_LIST_HEAD(&page->lru);
diff -puN arch/ppc64/mm/hugetlbpage.c~compound-pages-stop-using-lru arch/ppc64/mm/hugetlbpage.c
--- 25/arch/ppc64/mm/hugetlbpage.c~compound-pages-stop-using-lru 2004-03-26 12:36:42.008713328 -0800
+++ 25-akpm/arch/ppc64/mm/hugetlbpage.c 2004-03-26 12:36:42.016712112 -0800
@@ -407,7 +407,6 @@ follow_huge_pmd(struct mm_struct *mm, un
static void free_huge_page(struct page *page)
{
BUG_ON(page_count(page));
- BUG_ON(page->mapping);
INIT_LIST_HEAD(&page->lru);
diff -puN arch/sparc64/mm/hugetlbpage.c~compound-pages-stop-using-lru arch/sparc64/mm/hugetlbpage.c
--- 25/arch/sparc64/mm/hugetlbpage.c~compound-pages-stop-using-lru 2004-03-26 12:36:42.010713024 -0800
+++ 25-akpm/arch/sparc64/mm/hugetlbpage.c 2004-03-26 12:36:42.017711960 -0800
@@ -248,7 +248,6 @@ struct page *follow_huge_pmd(struct mm_s
static void free_huge_page(struct page *page)
{
BUG_ON(page_count(page));
- BUG_ON(page->mapping);
INIT_LIST_HEAD(&page->lru);
_