mm: Avoid putting a bad page back on the LRU v2

Prevent a page with a physical memory error from being placed back on the LRU. A new page flag (PG_memerror) is added on 64 bit architectures.

---
 include/linux/mm.h         |    8 +++++++-
 include/linux/page-flags.h |    8 ++++++++
 include/linux/swap.h       |    1 +
 mm/migrate.c               |    3 +++
 mm/page_alloc.c            |    9 +++++----
 mm/swap.c                  |    4 ++++
 6 files changed, 28 insertions(+), 5 deletions(-)

Index: linus/mm/page_alloc.c
=================================--- linus.orig/mm/page_alloc.c 2008-05-01 19:06:04.000000000 -0500
+++ linus/mm/page_alloc.c 2008-05-01 19:06:15.000000000 -0500
@@ -71,6 +71,7 @@ unsigned long totalram_pages __read_most
unsigned long totalreserve_pages __read_mostly; long nr_swap_pages;
int percpu_pagelist_fraction;
+unsigned int totalbad_pages;

#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
@@ -602,10 +603,10 @@ static int prep_new_page(struct page *pa
bad_page(page);

/*
- * For now, we report if PG_reserved was found set, but do not
- * clear it, and do not allocate the page: as a safety net.
+ * For now, we report if PG_reserved or PG_memerror was found set, but
+ * do not clear it, and do not allocate the page: as a safety net.
*/
- if (PageReserved(page))
+ if (PageReserved(page) || PageMemError(page))
return 1;

page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim |
@@ -2474,7 +2475,7 @@ static void setup_zone_migrate_reserve(s
page = pfn_to_page(pfn);

/* Blocks with reserved pages will never free, skip them. */
- if (PageReserved(page))
+ if (PageReserved(page) || PageMemError(page))
continue;

block_migratetype = get_pageblock_migratetype(page);
Index: linus/mm/swap.c
=================================--- linus.orig/mm/swap.c 2008-05-01 19:05:33.000000000 -0500
+++ linus/mm/swap.c 2008-05-01 19:06:15.000000000 -0500
@@ -195,6 +195,8 @@ void lru_cache_add(struct page *page)
struct pagevec *pvec = &get_cpu_var(lru_add_pvecs);

page_cache_get(page);
+ if (unlikely(PageMemError(page)))
+ return; /* Don't add bad pages to the page list */
if (!pagevec_add(pvec, page))
__pagevec_lru_add(pvec);
put_cpu_var(lru_add_pvecs);
@@ -205,6 +207,8 @@ void lru_cache_add_active(struct page *p
struct pagevec *pvec = &get_cpu_var(lru_add_active_pvecs);

page_cache_get(page);
+ if (unlikely(PageMemError(page)))
+ return; /* Don't add bad pages to the page list */
if (!pagevec_add(pvec, page))
__pagevec_lru_add_active(pvec);
put_cpu_var(lru_add_active_pvecs);
Index: linus/include/linux/swap.h
=================================--- linus.orig/include/linux/swap.h 2008-05-01 19:05:33.000000000 -0500
+++ linus/include/linux/swap.h 2008-05-01 19:06:15.000000000 -0500
@@ -165,6 +165,7 @@ extern unsigned long totalreserve_pages;
extern long nr_swap_pages;
extern unsigned int nr_free_buffer_pages(void); extern unsigned int nr_free_pagecache_pages(void);
+extern unsigned int totalbad_pages;

/* Definition of global_page_state not available yet */ #define nr_free_pages() global_page_state(NR_FREE_PAGES)
Index: linus/mm/migrate.c
=================================--- linus.orig/mm/migrate.c 2008-05-01 19:05:33.000000000 -0500
+++ linus/mm/migrate.c 2008-05-01 19:06:15.000000000 -0500
@@ -380,6 +380,7 @@ static void migrate_page_copy(struct pag
SetPageChecked(newpage);
if (PageMappedToDisk(page))
SetPageMappedToDisk(newpage);
+ /* Do not migrate PG_memerror to the new page */

if (PageDirty(page)) {
clear_page_dirty_for_io(page);
@@ -721,6 +722,8 @@ unlock:
*/
list_del(&page->lru);
move_to_lru(page);
+ if (PageMemError(page))
+ totalbad_pages++;
}

move_newpage:
Index: linus/include/linux/page-flags.h
=================================--- linus.orig/include/linux/page-flags.h 2008-05-01 19:05:33.000000000 -0500
+++ linus/include/linux/page-flags.h 2008-05-01 19:06:15.000000000 -0500
@@ -84,6 +84,7 @@ enum pageflags {
PG_private, /* If pagecache, has fs-private data */
PG_writeback, /* Page is under writeback */
#ifdef CONFIG_PAGEFLAGS_EXTENDED
+ PG_memerror, /* Page has a physical memory error */
PG_head, /* A head page */
PG_tail, /* A tail page */
#else
@@ -306,5 +307,12 @@ static inline void __ClearPageTail(struc
}

#endif /* !PAGEFLAGS_EXTENDED */
+
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+PAGEFLAG(MemError, memerror)
+#else
+#define PageMemError(page) 0
+#endif
+
#endif /* !__GENERATING_BOUNDS_H */
#endif /* PAGE_FLAGS_H */
Index: linus/include/linux/mm.h
=================================--- linus.orig/include/linux/mm.h 2008-05-01 19:06:04.000000000 -0500
+++ linus/include/linux/mm.h 2008-05-01 19:06:15.000000000 -0500
@@ -210,9 +210,15 @@ struct inode;
*/
#include <linux/page-flags.h>

-#define PAGE_FLAGS (1 << PG_lru | 1 << PG_private | 1 << PG_locked | \
+#define PAGE_FLAGS_BASE (1 << PG_lru | 1 << PG_private | 1 << PG_locked | \

 			 1 << PG_buddy | 1 << PG_writeback | \
 			 1 << PG_slab  | 1 << PG_swapcache | 1 << PG_active)

+
+#ifdef CONFIG_PAGEFLAGS_EXTENDED
+#define PAGE_FLAGS (PAGE_FLAGS_BASE | 1UL << PG_memerror)
+#else
+#define PAGE_FLAGS (PAGE_FLAGS_BASE)
+#endif

#define PAGE_FLAGS_RECLAIM (PAGE_FLAGS | 1 << PG_reclaim | 1 << PG_dirty)
#define PAGE_FLAGS_RESERVE (PAGE_FLAGS | 1 << PG_reserved)

Russ Anderson, OS RAS/Partitioning Project Lead  
SGI - Silicon Graphics Inc          [email protected]

To let anyone that may think PG_memerror should get copied to the new page that it should not. I can remove the comment.

It is only for accounting purposes, keeping a count of the bad pages.

OK.

page-flags.h is where I originally put them. Since they are only used in mm/page_alloc.c, I thought mm.h would be a more appropriate place. I can put them in page-flags.h.

Russ Anderson, OS RAS/Partitioning Project Lead  
SGI - Silicon Graphics Inc          [email protected]