You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
379 lines
14 KiB
379 lines
14 KiB
/*
|
|
* Macros for manipulating and testing page->flags
|
|
*/
|
|
|
|
#ifndef PAGE_FLAGS_H
|
|
#define PAGE_FLAGS_H
|
|
|
|
#include <linux/percpu.h>
|
|
#include <linux/cache.h>
|
|
#include <asm/pgtable.h>
|
|
|
|
/*
|
|
* Various page->flags bits:
|
|
*
|
|
* PG_reserved is set for special pages, which can never be swapped out. Some
|
|
* of them might not even exist (eg empty_bad_page)...
|
|
*
|
|
* The PG_private bitflag is set if page->private contains a valid value.
|
|
*
|
|
* During disk I/O, PG_locked is used. This bit is set before I/O and
|
|
* reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks
|
|
* waiting for the I/O on this page to complete.
|
|
*
|
|
* PG_uptodate tells whether the page's contents is valid. When a read
|
|
* completes, the page becomes uptodate, unless a disk I/O error happened.
|
|
*
|
|
* For choosing which pages to swap out, inode pages carry a PG_referenced bit,
|
|
* which is set any time the system accesses that page through the (mapping,
|
|
* index) hash table. This referenced bit, together with the referenced bit
|
|
* in the page tables, is used to manipulate page->age and move the page across
|
|
* the active, inactive_dirty and inactive_clean lists.
|
|
*
|
|
* Note that the referenced bit, the page->lru list_head and the active,
|
|
* inactive_dirty and inactive_clean lists are protected by the
|
|
* zone->lru_lock, and *NOT* by the usual PG_locked bit!
|
|
*
|
|
* PG_error is set to indicate that an I/O error occurred on this page.
|
|
*
|
|
* PG_arch_1 is an architecture specific page state bit. The generic code
|
|
* guarantees that this bit is cleared for a page when it first is entered into
|
|
* the page cache.
|
|
*
|
|
* PG_highmem pages are not permanently mapped into the kernel virtual address
|
|
* space, they need to be kmapped separately for doing IO on the pages. The
|
|
* struct page (these bits with information) are always mapped into kernel
|
|
* address space...
|
|
*/
|
|
|
|
/*
|
|
* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
|
|
* locked- and dirty-page accounting.
|
|
*
|
|
* The page flags field is split into two parts, the main flags area
|
|
* which extends from the low bits upwards, and the fields area which
|
|
* extends from the high bits downwards.
|
|
*
|
|
* | FIELD | ... | FLAGS |
|
|
* N-1 ^ 0
|
|
* (N-FLAGS_RESERVED)
|
|
*
|
|
* The fields area is reserved for fields mapping zone, node and SPARSEMEM
|
|
* section. The boundry between these two areas is defined by
|
|
* FLAGS_RESERVED which defines the width of the fields section
|
|
* (see linux/mmzone.h). New flags must _not_ overlap with this area.
|
|
*/
|
|
#define PG_locked 0 /* Page is locked. Don't touch. */
|
|
#define PG_error 1
|
|
#define PG_referenced 2
|
|
#define PG_uptodate 3
|
|
|
|
#define PG_dirty 4
|
|
#define PG_lru 5
|
|
#define PG_active 6
|
|
#define PG_slab 7 /* slab debug (Suparna wants this) */
|
|
|
|
#define PG_checked 8 /* kill me in 2.5.<early>. */
|
|
#define PG_arch_1 9
|
|
#define PG_reserved 10
|
|
#define PG_private 11 /* Has something at ->private */
|
|
|
|
#define PG_writeback 12 /* Page is under writeback */
|
|
#define PG_nosave 13 /* Used for system suspend/resume */
|
|
#define PG_compound 14 /* Part of a compound page */
|
|
#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
|
|
|
|
#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
|
|
#define PG_reclaim 17 /* To be reclaimed asap */
|
|
#define PG_nosave_free 18 /* Free, should not be written */
|
|
#define PG_buddy 19 /* Page is free, on buddy lists */
|
|
|
|
#define PG_uncached 20 /* Page has been mapped as uncached */
|
|
|
|
/*
|
|
* Global page accounting. One instance per CPU. Only unsigned longs are
|
|
* allowed.
|
|
*
|
|
* - Fields can be modified with xxx_page_state and xxx_page_state_zone at
|
|
* any time safely (which protects the instance from modification by
|
|
* interrupt.
|
|
* - The __xxx_page_state variants can be used safely when interrupts are
|
|
* disabled.
|
|
* - The __xxx_page_state variants can be used if the field is only
|
|
* modified from process context and protected from preemption, or only
|
|
* modified from interrupt context. In this case, the field should be
|
|
* commented here.
|
|
*/
|
|
struct page_state {
|
|
unsigned long nr_dirty; /* Dirty writeable pages */
|
|
unsigned long nr_writeback; /* Pages under writeback */
|
|
unsigned long nr_unstable; /* NFS unstable pages */
|
|
unsigned long nr_page_table_pages;/* Pages used for pagetables */
|
|
unsigned long nr_mapped; /* mapped into pagetables.
|
|
* only modified from process context */
|
|
unsigned long nr_slab; /* In slab */
|
|
#define GET_PAGE_STATE_LAST nr_slab
|
|
|
|
/*
|
|
* The below are zeroed by get_page_state(). Use get_full_page_state()
|
|
* to add up all these.
|
|
*/
|
|
unsigned long pgpgin; /* Disk reads */
|
|
unsigned long pgpgout; /* Disk writes */
|
|
unsigned long pswpin; /* swap reads */
|
|
unsigned long pswpout; /* swap writes */
|
|
|
|
unsigned long pgalloc_high; /* page allocations */
|
|
unsigned long pgalloc_normal;
|
|
unsigned long pgalloc_dma32;
|
|
unsigned long pgalloc_dma;
|
|
|
|
unsigned long pgfree; /* page freeings */
|
|
unsigned long pgactivate; /* pages moved inactive->active */
|
|
unsigned long pgdeactivate; /* pages moved active->inactive */
|
|
|
|
unsigned long pgfault; /* faults (major+minor) */
|
|
unsigned long pgmajfault; /* faults (major only) */
|
|
|
|
unsigned long pgrefill_high; /* inspected in refill_inactive_zone */
|
|
unsigned long pgrefill_normal;
|
|
unsigned long pgrefill_dma32;
|
|
unsigned long pgrefill_dma;
|
|
|
|
unsigned long pgsteal_high; /* total highmem pages reclaimed */
|
|
unsigned long pgsteal_normal;
|
|
unsigned long pgsteal_dma32;
|
|
unsigned long pgsteal_dma;
|
|
|
|
unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
|
|
unsigned long pgscan_kswapd_normal;
|
|
unsigned long pgscan_kswapd_dma32;
|
|
unsigned long pgscan_kswapd_dma;
|
|
|
|
unsigned long pgscan_direct_high;/* total highmem pages scanned */
|
|
unsigned long pgscan_direct_normal;
|
|
unsigned long pgscan_direct_dma32;
|
|
unsigned long pgscan_direct_dma;
|
|
|
|
unsigned long pginodesteal; /* pages reclaimed via inode freeing */
|
|
unsigned long slabs_scanned; /* slab objects scanned */
|
|
unsigned long kswapd_steal; /* pages reclaimed by kswapd */
|
|
unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
|
|
unsigned long pageoutrun; /* kswapd's calls to page reclaim */
|
|
unsigned long allocstall; /* direct reclaim calls */
|
|
|
|
unsigned long pgrotated; /* pages rotated to tail of the LRU */
|
|
unsigned long nr_bounce; /* pages for bounce buffers */
|
|
};
|
|
|
|
extern void get_page_state(struct page_state *ret);
|
|
extern void get_page_state_node(struct page_state *ret, int node);
|
|
extern void get_full_page_state(struct page_state *ret);
|
|
extern unsigned long read_page_state_offset(unsigned long offset);
|
|
extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
|
|
extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
|
|
|
|
#define read_page_state(member) \
|
|
read_page_state_offset(offsetof(struct page_state, member))
|
|
|
|
#define mod_page_state(member, delta) \
|
|
mod_page_state_offset(offsetof(struct page_state, member), (delta))
|
|
|
|
#define __mod_page_state(member, delta) \
|
|
__mod_page_state_offset(offsetof(struct page_state, member), (delta))
|
|
|
|
#define inc_page_state(member) mod_page_state(member, 1UL)
|
|
#define dec_page_state(member) mod_page_state(member, 0UL - 1)
|
|
#define add_page_state(member,delta) mod_page_state(member, (delta))
|
|
#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
|
|
|
|
#define __inc_page_state(member) __mod_page_state(member, 1UL)
|
|
#define __dec_page_state(member) __mod_page_state(member, 0UL - 1)
|
|
#define __add_page_state(member,delta) __mod_page_state(member, (delta))
|
|
#define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta))
|
|
|
|
#define page_state(member) (*__page_state(offsetof(struct page_state, member)))
|
|
|
|
#define state_zone_offset(zone, member) \
|
|
({ \
|
|
unsigned offset; \
|
|
if (is_highmem(zone)) \
|
|
offset = offsetof(struct page_state, member##_high); \
|
|
else if (is_normal(zone)) \
|
|
offset = offsetof(struct page_state, member##_normal); \
|
|
else if (is_dma32(zone)) \
|
|
offset = offsetof(struct page_state, member##_dma32); \
|
|
else \
|
|
offset = offsetof(struct page_state, member##_dma); \
|
|
offset; \
|
|
})
|
|
|
|
#define __mod_page_state_zone(zone, member, delta) \
|
|
do { \
|
|
__mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
|
|
} while (0)
|
|
|
|
#define mod_page_state_zone(zone, member, delta) \
|
|
do { \
|
|
mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
|
|
} while (0)
|
|
|
|
/*
|
|
* Manipulation of page state flags
|
|
*/
|
|
#define PageLocked(page) \
|
|
test_bit(PG_locked, &(page)->flags)
|
|
#define SetPageLocked(page) \
|
|
set_bit(PG_locked, &(page)->flags)
|
|
#define TestSetPageLocked(page) \
|
|
test_and_set_bit(PG_locked, &(page)->flags)
|
|
#define ClearPageLocked(page) \
|
|
clear_bit(PG_locked, &(page)->flags)
|
|
#define TestClearPageLocked(page) \
|
|
test_and_clear_bit(PG_locked, &(page)->flags)
|
|
|
|
#define PageError(page) test_bit(PG_error, &(page)->flags)
|
|
#define SetPageError(page) set_bit(PG_error, &(page)->flags)
|
|
#define ClearPageError(page) clear_bit(PG_error, &(page)->flags)
|
|
|
|
#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags)
|
|
#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
|
|
#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
|
|
#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
|
|
|
|
#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
|
|
#ifndef SetPageUptodate
|
|
#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
|
|
#endif
|
|
#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
|
|
|
|
#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
|
|
#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags)
|
|
#define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags)
|
|
#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags)
|
|
#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags)
|
|
#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
|
|
|
|
#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
|
|
#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
|
|
#define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags)
|
|
#define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags)
|
|
|
|
#define PageActive(page) test_bit(PG_active, &(page)->flags)
|
|
#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
|
|
#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
|
|
#define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags)
|
|
|
|
#define PageSlab(page) test_bit(PG_slab, &(page)->flags)
|
|
#define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags)
|
|
#define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags)
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
#define PageHighMem(page) is_highmem(page_zone(page))
|
|
#else
|
|
#define PageHighMem(page) 0 /* needed to optimize away at compile time */
|
|
#endif
|
|
|
|
#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
|
|
#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
|
|
#define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags)
|
|
|
|
#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
|
|
#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
|
|
#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
|
|
#define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags)
|
|
|
|
#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags)
|
|
#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags)
|
|
#define PagePrivate(page) test_bit(PG_private, &(page)->flags)
|
|
#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags)
|
|
#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
|
|
|
|
#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
|
|
#define SetPageWriteback(page) \
|
|
do { \
|
|
if (!test_and_set_bit(PG_writeback, \
|
|
&(page)->flags)) \
|
|
inc_page_state(nr_writeback); \
|
|
} while (0)
|
|
#define TestSetPageWriteback(page) \
|
|
({ \
|
|
int ret; \
|
|
ret = test_and_set_bit(PG_writeback, \
|
|
&(page)->flags); \
|
|
if (!ret) \
|
|
inc_page_state(nr_writeback); \
|
|
ret; \
|
|
})
|
|
#define ClearPageWriteback(page) \
|
|
do { \
|
|
if (test_and_clear_bit(PG_writeback, \
|
|
&(page)->flags)) \
|
|
dec_page_state(nr_writeback); \
|
|
} while (0)
|
|
#define TestClearPageWriteback(page) \
|
|
({ \
|
|
int ret; \
|
|
ret = test_and_clear_bit(PG_writeback, \
|
|
&(page)->flags); \
|
|
if (ret) \
|
|
dec_page_state(nr_writeback); \
|
|
ret; \
|
|
})
|
|
|
|
#define PageNosave(page) test_bit(PG_nosave, &(page)->flags)
|
|
#define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags)
|
|
#define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags)
|
|
#define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags)
|
|
#define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags)
|
|
|
|
#define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags)
|
|
#define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags)
|
|
#define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags)
|
|
|
|
#define PageBuddy(page) test_bit(PG_buddy, &(page)->flags)
|
|
#define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags)
|
|
#define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags)
|
|
|
|
#define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags)
|
|
#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
|
|
#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
|
|
|
|
#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags)
|
|
#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags)
|
|
#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
|
|
#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
|
|
|
|
#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
|
|
#define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags)
|
|
#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
|
|
|
|
#ifdef CONFIG_SWAP
|
|
#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)
|
|
#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
|
|
#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
|
|
#else
|
|
#define PageSwapCache(page) 0
|
|
#endif
|
|
|
|
#define PageUncached(page) test_bit(PG_uncached, &(page)->flags)
|
|
#define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags)
|
|
#define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags)
|
|
|
|
struct page; /* forward declaration */
|
|
|
|
int test_clear_page_dirty(struct page *page);
|
|
int test_clear_page_writeback(struct page *page);
|
|
int test_set_page_writeback(struct page *page);
|
|
|
|
static inline void clear_page_dirty(struct page *page)
|
|
{
|
|
test_clear_page_dirty(page);
|
|
}
|
|
|
|
static inline void set_page_writeback(struct page *page)
|
|
{
|
|
test_set_page_writeback(page);
|
|
}
|
|
|
|
#endif /* PAGE_FLAGS_H */
|
|
|