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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Macros for manipulating and testing page->flags
3 */
4
5#ifndef PAGE_FLAGS_H
6#define PAGE_FLAGS_H
7
Andrew Mortonf886ed42006-06-23 02:03:06 -07008#include <linux/types.h>
Christoph Lameter9223b412008-04-28 02:12:48 -07009#ifndef __GENERATING_BOUNDS_H
Christoph Lameter6d777952007-05-06 14:49:40 -070010#include <linux/mm_types.h>
Christoph Lameter9223b412008-04-28 02:12:48 -070011#include <linux/bounds.h>
12#endif /* !__GENERATING_BOUNDS_H */
Andrew Mortonf886ed42006-06-23 02:03:06 -070013
Linus Torvalds1da177e2005-04-16 15:20:36 -070014/*
15 * Various page->flags bits:
16 *
17 * PG_reserved is set for special pages, which can never be swapped out. Some
18 * of them might not even exist (eg empty_bad_page)...
19 *
Nick Pigginda6052f2006-09-25 23:31:35 -070020 * The PG_private bitflag is set on pagecache pages if they contain filesystem
21 * specific data (which is normally at page->private). It can be used by
22 * private allocations for its own usage.
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 *
Nick Pigginda6052f2006-09-25 23:31:35 -070024 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O
25 * and cleared when writeback _starts_ or when read _completes_. PG_writeback
26 * is set before writeback starts and cleared when it finishes.
27 *
28 * PG_locked also pins a page in pagecache, and blocks truncation of the file
29 * while it is held.
30 *
31 * page_waitqueue(page) is a wait queue of all tasks waiting for the page
32 * to become unlocked.
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 *
34 * PG_uptodate tells whether the page's contents is valid. When a read
35 * completes, the page becomes uptodate, unless a disk I/O error happened.
36 *
Nick Pigginda6052f2006-09-25 23:31:35 -070037 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
38 * file-backed pagecache (see mm/vmscan.c).
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 *
40 * PG_error is set to indicate that an I/O error occurred on this page.
41 *
42 * PG_arch_1 is an architecture specific page state bit. The generic code
43 * guarantees that this bit is cleared for a page when it first is entered into
44 * the page cache.
45 *
46 * PG_highmem pages are not permanently mapped into the kernel virtual address
47 * space, they need to be kmapped separately for doing IO on the pages. The
48 * struct page (these bits with information) are always mapped into kernel
49 * address space...
Nick Pigginda6052f2006-09-25 23:31:35 -070050 *
51 * PG_buddy is set to indicate that the page is free and in the buddy system
52 * (see mm/page_alloc.c).
53 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 */
55
56/*
57 * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
Andy Whitcroft91fc8ab2006-04-10 22:53:01 -070058 * locked- and dirty-page accounting.
59 *
60 * The page flags field is split into two parts, the main flags area
61 * which extends from the low bits upwards, and the fields area which
62 * extends from the high bits downwards.
63 *
64 * | FIELD | ... | FLAGS |
Christoph Lameter9223b412008-04-28 02:12:48 -070065 * N-1 ^ 0
66 * (NR_PAGEFLAGS)
Andy Whitcroft91fc8ab2006-04-10 22:53:01 -070067 *
Christoph Lameter9223b412008-04-28 02:12:48 -070068 * The fields area is reserved for fields mapping zone, node (for NUMA) and
69 * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
70 * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 */
Christoph Lametere2683182008-04-28 02:12:47 -070072enum pageflags {
73 PG_locked, /* Page is locked. Don't touch. */
74 PG_error,
75 PG_referenced,
76 PG_uptodate,
77 PG_dirty,
78 PG_lru,
79 PG_active,
80 PG_slab,
81 PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
Christoph Lametere2683182008-04-28 02:12:47 -070082 PG_arch_1,
83 PG_reserved,
84 PG_private, /* If pagecache, has fs-private data */
David Howells266cf652009-04-03 16:42:36 +010085 PG_private_2, /* If pagecache, has fs aux data */
Christoph Lametere2683182008-04-28 02:12:47 -070086 PG_writeback, /* Page is under writeback */
Christoph Lametere20b8cc2008-04-28 02:12:55 -070087#ifdef CONFIG_PAGEFLAGS_EXTENDED
88 PG_head, /* A head page */
89 PG_tail, /* A tail page */
90#else
Christoph Lametere2683182008-04-28 02:12:47 -070091 PG_compound, /* A compound page */
Christoph Lametere20b8cc2008-04-28 02:12:55 -070092#endif
Christoph Lametere2683182008-04-28 02:12:47 -070093 PG_swapcache, /* Swap page: swp_entry_t in private */
94 PG_mappedtodisk, /* Has blocks allocated on-disk */
95 PG_reclaim, /* To be reclaimed asap */
Christoph Lametere2683182008-04-28 02:12:47 -070096 PG_buddy, /* Page is free, on buddy lists */
Rik van Rielb2e18532008-10-18 20:26:30 -070097 PG_swapbacked, /* Page is backed by RAM/swap */
Lee Schermerhorn894bc312008-10-18 20:26:39 -070098#ifdef CONFIG_UNEVICTABLE_LRU
99 PG_unevictable, /* Page is "unevictable" */
David Howells33925b22009-03-31 15:23:26 -0700100#endif
101#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
Nick Pigginb291f002008-10-18 20:26:44 -0700102 PG_mlocked, /* Page is vma mlocked */
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700103#endif
Christoph Lameter602c4d12008-04-28 02:12:52 -0700104#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
105 PG_uncached, /* Page has been mapped as uncached */
Andrew Mortonf886ed42006-06-23 02:03:06 -0700106#endif
Andy Whitcroft0cad47c2008-07-23 21:27:16 -0700107 __NR_PAGEFLAGS,
108
109 /* Filesystems */
110 PG_checked = PG_owner_priv_1,
111
David Howells266cf652009-04-03 16:42:36 +0100112 /* Two page bits are conscripted by FS-Cache to maintain local caching
113 * state. These bits are set on pages belonging to the netfs's inodes
114 * when those inodes are being locally cached.
115 */
116 PG_fscache = PG_private_2, /* page backed by cache */
117
Andy Whitcroft0cad47c2008-07-23 21:27:16 -0700118 /* XEN */
119 PG_pinned = PG_owner_priv_1,
120 PG_savepinned = PG_dirty,
Andy Whitcroft8a380822008-07-23 21:27:18 -0700121
Andy Whitcroft9023cb72008-07-23 21:27:19 -0700122 /* SLOB */
123 PG_slob_page = PG_active,
124 PG_slob_free = PG_private,
125
Andy Whitcroft8a380822008-07-23 21:27:18 -0700126 /* SLUB */
127 PG_slub_frozen = PG_active,
128 PG_slub_debug = PG_error,
Christoph Lametere2683182008-04-28 02:12:47 -0700129};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Christoph Lameter9223b412008-04-28 02:12:48 -0700131#ifndef __GENERATING_BOUNDS_H
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/*
Christoph Lameterf94a62e2008-04-28 02:12:49 -0700134 * Macros to create function definitions for page flags
135 */
136#define TESTPAGEFLAG(uname, lname) \
137static inline int Page##uname(struct page *page) \
138 { return test_bit(PG_##lname, &page->flags); }
139
140#define SETPAGEFLAG(uname, lname) \
141static inline void SetPage##uname(struct page *page) \
142 { set_bit(PG_##lname, &page->flags); }
143
144#define CLEARPAGEFLAG(uname, lname) \
145static inline void ClearPage##uname(struct page *page) \
146 { clear_bit(PG_##lname, &page->flags); }
147
148#define __SETPAGEFLAG(uname, lname) \
149static inline void __SetPage##uname(struct page *page) \
150 { __set_bit(PG_##lname, &page->flags); }
151
152#define __CLEARPAGEFLAG(uname, lname) \
153static inline void __ClearPage##uname(struct page *page) \
154 { __clear_bit(PG_##lname, &page->flags); }
155
156#define TESTSETFLAG(uname, lname) \
157static inline int TestSetPage##uname(struct page *page) \
158 { return test_and_set_bit(PG_##lname, &page->flags); }
159
160#define TESTCLEARFLAG(uname, lname) \
161static inline int TestClearPage##uname(struct page *page) \
162 { return test_and_clear_bit(PG_##lname, &page->flags); }
163
164
165#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
166 SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)
167
168#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
169 __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname)
170
Christoph Lameterec7cade2008-04-28 02:12:53 -0700171#define PAGEFLAG_FALSE(uname) \
172static inline int Page##uname(struct page *page) \
173 { return 0; }
174
Christoph Lameterf94a62e2008-04-28 02:12:49 -0700175#define TESTSCFLAG(uname, lname) \
176 TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)
177
Lee Schermerhorn8a7a8542008-10-18 20:26:37 -0700178#define SETPAGEFLAG_NOOP(uname) \
179static inline void SetPage##uname(struct page *page) { }
180
181#define CLEARPAGEFLAG_NOOP(uname) \
182static inline void ClearPage##uname(struct page *page) { }
183
184#define __CLEARPAGEFLAG_NOOP(uname) \
185static inline void __ClearPage##uname(struct page *page) { }
186
187#define TESTCLEARFLAG_FALSE(uname) \
188static inline int TestClearPage##uname(struct page *page) { return 0; }
189
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700190struct page; /* forward declaration */
191
David Howells03fb3d22009-04-03 16:42:35 +0100192TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700193PAGEFLAG(Error, error)
194PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
195PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
196PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
197PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active)
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700198 TESTCLEARFLAG(Active, active)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700199__PAGEFLAG(Slab, slab)
Andy Whitcroft0cad47c2008-07-23 21:27:16 -0700200PAGEFLAG(Checked, checked) /* Used by some filesystems */
201PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */
202PAGEFLAG(SavePinned, savepinned); /* Xen */
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700203PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
Rik van Rielb2e18532008-10-18 20:26:30 -0700204PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700205
Andy Whitcroft9023cb72008-07-23 21:27:19 -0700206__PAGEFLAG(SlobPage, slob_page)
207__PAGEFLAG(SlobFree, slob_free)
208
Andy Whitcroft8a380822008-07-23 21:27:18 -0700209__PAGEFLAG(SlubFrozen, slub_frozen)
210__PAGEFLAG(SlubDebug, slub_debug)
211
Christoph Lameterf94a62e2008-04-28 02:12:49 -0700212/*
David Howells266cf652009-04-03 16:42:36 +0100213 * Private page markings that may be used by the filesystem that owns the page
214 * for its own purposes.
215 * - PG_private and PG_private_2 cause releasepage() and co to be invoked
216 */
217PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private)
218 __CLEARPAGEFLAG(Private, private)
219PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2)
220PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1)
221
222/*
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700223 * Only test-and-set exist for PG_writeback. The unconditional operators are
224 * risky: they bypass page accounting.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 */
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700226TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback)
227__PAGEFLAG(Buddy, buddy)
228PAGEFLAG(MappedToDisk, mappedtodisk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700230/* PG_readahead is only used for file reads; PG_reclaim is only for writes */
231PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim)
Christoph Lameter0a128b22008-04-28 02:12:52 -0700232PAGEFLAG(Readahead, reclaim) /* Reminder to do async read-ahead */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700234#ifdef CONFIG_HIGHMEM
235/*
236 * Must use a macro here due to header dependency issues. page_zone() is not
237 * available at this point.
238 */
Christoph Lameter0a128b22008-04-28 02:12:52 -0700239#define PageHighMem(__p) is_highmem(page_zone(__p))
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700240#else
Christoph Lameterec7cade2008-04-28 02:12:53 -0700241PAGEFLAG_FALSE(HighMem)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700242#endif
243
244#ifdef CONFIG_SWAP
245PAGEFLAG(SwapCache, swapcache)
246#else
Christoph Lameterec7cade2008-04-28 02:12:53 -0700247PAGEFLAG_FALSE(SwapCache)
Hugh Dickins6d91add2009-01-06 14:39:24 -0800248 SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700249#endif
250
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700251#ifdef CONFIG_UNEVICTABLE_LRU
252PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable)
253 TESTCLEARFLAG(Unevictable, unevictable)
254#else
255PAGEFLAG_FALSE(Unevictable) TESTCLEARFLAG_FALSE(Unevictable)
256 SETPAGEFLAG_NOOP(Unevictable) CLEARPAGEFLAG_NOOP(Unevictable)
257 __CLEARPAGEFLAG_NOOP(Unevictable)
258#endif
259
David Howells33925b22009-03-31 15:23:26 -0700260#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
261#define MLOCK_PAGES 1
262PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked)
263 TESTSCFLAG(Mlocked, mlocked)
264#else
265#define MLOCK_PAGES 0
266PAGEFLAG_FALSE(Mlocked)
267 SETPAGEFLAG_NOOP(Mlocked) TESTCLEARFLAG_FALSE(Mlocked)
268#endif
269
Christoph Lameter602c4d12008-04-28 02:12:52 -0700270#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700271PAGEFLAG(Uncached, uncached)
Christoph Lameter602c4d12008-04-28 02:12:52 -0700272#else
Christoph Lameterec7cade2008-04-28 02:12:53 -0700273PAGEFLAG_FALSE(Uncached)
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700274#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
Nick Piggin0ed361d2008-02-04 22:29:34 -0800276static inline int PageUptodate(struct page *page)
277{
278 int ret = test_bit(PG_uptodate, &(page)->flags);
279
280 /*
281 * Must ensure that the data we read out of the page is loaded
282 * _after_ we've loaded page->flags to check for PageUptodate.
283 * We can skip the barrier if the page is not uptodate, because
284 * we wouldn't be reading anything from it.
285 *
286 * See SetPageUptodate() for the other side of the story.
287 */
288 if (ret)
289 smp_rmb();
290
291 return ret;
292}
293
294static inline void __SetPageUptodate(struct page *page)
295{
296 smp_wmb();
297 __set_bit(PG_uptodate, &(page)->flags);
Nick Piggin0ed361d2008-02-04 22:29:34 -0800298}
299
Heiko Carstens2dcea572006-09-29 01:58:41 -0700300static inline void SetPageUptodate(struct page *page)
301{
Nick Piggin0ed361d2008-02-04 22:29:34 -0800302#ifdef CONFIG_S390
Heiko Carstens2dcea572006-09-29 01:58:41 -0700303 if (!test_and_set_bit(PG_uptodate, &page->flags))
Martin Schwidefsky6c210482007-04-27 16:01:57 +0200304 page_clear_dirty(page);
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700305#else
Nick Piggin0ed361d2008-02-04 22:29:34 -0800306 /*
307 * Memory barrier must be issued before setting the PG_uptodate bit,
308 * so that all previous stores issued in order to bring the page
309 * uptodate are actually visible before PageUptodate becomes true.
310 *
311 * s390 doesn't need an explicit smp_wmb here because the test and
312 * set bit already provides full barriers.
313 */
314 smp_wmb();
315 set_bit(PG_uptodate, &(page)->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316#endif
Nick Piggin0ed361d2008-02-04 22:29:34 -0800317}
318
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700319CLEARPAGEFLAG(Uptodate, uptodate)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Linus Torvaldsfba25912006-12-20 13:46:42 -0800321extern void cancel_dirty_page(struct page *page, unsigned int account_size);
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323int test_clear_page_writeback(struct page *page);
324int test_set_page_writeback(struct page *page);
325
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326static inline void set_page_writeback(struct page *page)
327{
328 test_set_page_writeback(page);
329}
330
Christoph Lametere20b8cc2008-04-28 02:12:55 -0700331#ifdef CONFIG_PAGEFLAGS_EXTENDED
332/*
333 * System with lots of page flags available. This allows separate
334 * flags for PageHead() and PageTail() checks of compound pages so that bit
335 * tests can be used in performance sensitive paths. PageCompound is
336 * generally not used in hot code paths.
337 */
338__PAGEFLAG(Head, head)
339__PAGEFLAG(Tail, tail)
340
341static inline int PageCompound(struct page *page)
342{
343 return page->flags & ((1L << PG_head) | (1L << PG_tail));
344
345}
346#else
347/*
348 * Reduce page flag use as much as possible by overlapping
349 * compound page flags with the flags used for page cache pages. Possible
350 * because PageCompound is always set for compound pages and not for
351 * pages on the LRU and/or pagecache.
352 */
Christoph Lameter6a1e7f772008-04-28 02:12:50 -0700353TESTPAGEFLAG(Compound, compound)
354__PAGEFLAG(Head, compound)
355
356/*
357 * PG_reclaim is used in combination with PG_compound to mark the
358 * head and tail of a compound page. This saves one page flag
359 * but makes it impossible to use compound pages for the page cache.
360 * The PG_reclaim bit would have to be used for reclaim or readahead
361 * if compound pages enter the page cache.
362 *
363 * PG_compound & PG_reclaim => Tail page
364 * PG_compound & ~PG_reclaim => Head page
365 */
366#define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim))
367
368static inline int PageTail(struct page *page)
369{
370 return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask);
371}
372
373static inline void __SetPageTail(struct page *page)
374{
375 page->flags |= PG_head_tail_mask;
376}
377
378static inline void __ClearPageTail(struct page *page)
379{
380 page->flags &= ~PG_head_tail_mask;
381}
382
Christoph Lametere20b8cc2008-04-28 02:12:55 -0700383#endif /* !PAGEFLAGS_EXTENDED */
Russ Andersondfa7e202008-06-09 11:18:45 -0500384
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700385#ifdef CONFIG_UNEVICTABLE_LRU
Nick Pigginb291f002008-10-18 20:26:44 -0700386#define __PG_UNEVICTABLE (1 << PG_unevictable)
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700387#else
Nick Pigginb291f002008-10-18 20:26:44 -0700388#define __PG_UNEVICTABLE 0
David Howells33925b22009-03-31 15:23:26 -0700389#endif
390
391#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
392#define __PG_MLOCKED (1 << PG_mlocked)
393#else
Nick Pigginb291f002008-10-18 20:26:44 -0700394#define __PG_MLOCKED 0
Lee Schermerhorn894bc312008-10-18 20:26:39 -0700395#endif
396
Russ Andersondfa7e202008-06-09 11:18:45 -0500397/*
398 * Flags checked when a page is freed. Pages being freed should not have
399 * these flags set. It they are, there is a problem.
400 */
Hugh Dickins79f4b7b2009-01-06 14:40:05 -0800401#define PAGE_FLAGS_CHECK_AT_FREE \
David Howells266cf652009-04-03 16:42:36 +0100402 (1 << PG_lru | 1 << PG_locked | \
403 1 << PG_private | 1 << PG_private_2 | \
404 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \
405 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
Hugh Dickins79f4b7b2009-01-06 14:40:05 -0800406 __PG_UNEVICTABLE | __PG_MLOCKED)
Russ Andersondfa7e202008-06-09 11:18:45 -0500407
408/*
409 * Flags checked when a page is prepped for return by the page allocator.
Hugh Dickins79f4b7b2009-01-06 14:40:05 -0800410 * Pages being prepped should not have any flags set. It they are set,
411 * there has been a kernel bug or struct page corruption.
Russ Andersondfa7e202008-06-09 11:18:45 -0500412 */
Hugh Dickins79f4b7b2009-01-06 14:40:05 -0800413#define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1)
Russ Andersondfa7e202008-06-09 11:18:45 -0500414
Christoph Lameter9223b412008-04-28 02:12:48 -0700415#endif /* !__GENERATING_BOUNDS_H */
David Howells266cf652009-04-03 16:42:36 +0100416
417/**
418 * page_has_private - Determine if page has private stuff
419 * @page: The page to be checked
420 *
421 * Determine if a page has private stuff, indicating that release routines
422 * should be invoked upon it.
423 */
424#define page_has_private(page) \
425 ((page)->flags & ((1 << PG_private) | \
426 (1 << PG_private_2)))
427
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428#endif /* PAGE_FLAGS_H */