[PATCH] own header file for struct page
This moves the definition of struct page from mm.h to its own header file
page-struct.h. This is a prereq to fix SetPageUptodate which is broken on
s390:
#define SetPageUptodate(_page)
do {
struct page *__page = (_page);
if (!test_and_set_bit(PG_uptodate, &__page->flags))
page_test_and_clear_dirty(_page);
} while (0)
_page gets used twice in this macro which can cause subtle bugs. Using
__page for the page_test_and_clear_dirty call doesn't work since it causes
yet another problem with the page_test_and_clear_dirty macro as well.
In order to avoid all these problems caused by macros it seems to be a good
idea to get rid of them and convert them to static inline functions.
Because of header file include order it's necessary to have a seperate
header file for the struct page definition.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9d046db..7477fb5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -16,6 +16,7 @@
#include <linux/mutex.h>
#include <linux/debug_locks.h>
#include <linux/backing-dev.h>
+#include <linux/mm_types.h>
struct mempolicy;
struct anon_vma;
@@ -215,62 +216,6 @@
struct mmu_gather;
struct inode;
-/*
- * Each physical page in the system has a struct page associated with
- * it to keep track of whatever it is we are using the page for at the
- * moment. Note that we have no way to track which tasks are using
- * a page, though if it is a pagecache page, rmap structures can tell us
- * who is mapping it.
- */
-struct page {
- unsigned long flags; /* Atomic flags, some possibly
- * updated asynchronously */
- atomic_t _count; /* Usage count, see below. */
- atomic_t _mapcount; /* Count of ptes mapped in mms,
- * to show when page is mapped
- * & limit reverse map searches.
- */
- union {
- struct {
- unsigned long private; /* Mapping-private opaque data:
- * usually used for buffer_heads
- * if PagePrivate set; used for
- * swp_entry_t if PageSwapCache;
- * indicates order in the buddy
- * system if PG_buddy is set.
- */
- struct address_space *mapping; /* If low bit clear, points to
- * inode address_space, or NULL.
- * If page mapped as anonymous
- * memory, low bit is set, and
- * it points to anon_vma object:
- * see PAGE_MAPPING_ANON below.
- */
- };
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
- spinlock_t ptl;
-#endif
- };
- pgoff_t index; /* Our offset within mapping. */
- struct list_head lru; /* Pageout list, eg. active_list
- * protected by zone->lru_lock !
- */
- /*
- * On machines where all RAM is mapped into kernel address space,
- * we can simply calculate the virtual address. On machines with
- * highmem some memory is mapped into kernel virtual memory
- * dynamically, so we need a place to store that address.
- * Note that this field could be 16 bits on x86 ... ;)
- *
- * Architectures with slow multiplication can define
- * WANT_PAGE_VIRTUAL in asm/page.h
- */
-#if defined(WANT_PAGE_VIRTUAL)
- void *virtual; /* Kernel virtual address (NULL if
- not kmapped, ie. highmem) */
-#endif /* WANT_PAGE_VIRTUAL */
-};
-
#define page_private(page) ((page)->private)
#define set_page_private(page, v) ((page)->private = (v))
@@ -546,11 +491,6 @@
*/
#include <linux/vmstat.h>
-#ifndef CONFIG_DISCONTIGMEM
-/* The array of struct pages - for discontigmem use pgdat->lmem_map */
-extern struct page *mem_map;
-#endif
-
static __always_inline void *lowmem_page_address(struct page *page)
{
return __va(page_to_pfn(page) << PAGE_SHIFT);