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-rw-r--r--include/linux/page-flags.h183
1 files changed, 31 insertions, 152 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 0c076d58c67..4830a3bedfb 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -5,36 +5,33 @@
5#ifndef PAGE_FLAGS_H 5#ifndef PAGE_FLAGS_H
6#define PAGE_FLAGS_H 6#define PAGE_FLAGS_H
7 7
8#include <linux/percpu.h>
9#include <linux/cache.h>
10#include <linux/types.h> 8#include <linux/types.h>
11 9
12#include <asm/pgtable.h>
13
14/* 10/*
15 * Various page->flags bits: 11 * Various page->flags bits:
16 * 12 *
17 * PG_reserved is set for special pages, which can never be swapped out. Some 13 * 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)... 14 * of them might not even exist (eg empty_bad_page)...
19 * 15 *
20 * The PG_private bitflag is set if page->private contains a valid value. 16 * The PG_private bitflag is set on pagecache pages if they contain filesystem
17 * specific data (which is normally at page->private). It can be used by
18 * private allocations for its own usage.
19 *
20 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O
21 * and cleared when writeback _starts_ or when read _completes_. PG_writeback
22 * is set before writeback starts and cleared when it finishes.
21 * 23 *
22 * During disk I/O, PG_locked is used. This bit is set before I/O and 24 * PG_locked also pins a page in pagecache, and blocks truncation of the file
23 * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks 25 * while it is held.
24 * waiting for the I/O on this page to complete. 26 *
27 * page_waitqueue(page) is a wait queue of all tasks waiting for the page
28 * to become unlocked.
25 * 29 *
26 * PG_uptodate tells whether the page's contents is valid. When a read 30 * PG_uptodate tells whether the page's contents is valid. When a read
27 * completes, the page becomes uptodate, unless a disk I/O error happened. 31 * completes, the page becomes uptodate, unless a disk I/O error happened.
28 * 32 *
29 * For choosing which pages to swap out, inode pages carry a PG_referenced bit, 33 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
30 * which is set any time the system accesses that page through the (mapping, 34 * file-backed pagecache (see mm/vmscan.c).
31 * index) hash table. This referenced bit, together with the referenced bit
32 * in the page tables, is used to manipulate page->age and move the page across
33 * the active, inactive_dirty and inactive_clean lists.
34 *
35 * Note that the referenced bit, the page->lru list_head and the active,
36 * inactive_dirty and inactive_clean lists are protected by the
37 * zone->lru_lock, and *NOT* by the usual PG_locked bit!
38 * 35 *
39 * PG_error is set to indicate that an I/O error occurred on this page. 36 * PG_error is set to indicate that an I/O error occurred on this page.
40 * 37 *
@@ -46,6 +43,10 @@
46 * space, they need to be kmapped separately for doing IO on the pages. The 43 * space, they need to be kmapped separately for doing IO on the pages. The
47 * struct page (these bits with information) are always mapped into kernel 44 * struct page (these bits with information) are always mapped into kernel
48 * address space... 45 * address space...
46 *
47 * PG_buddy is set to indicate that the page is free and in the buddy system
48 * (see mm/page_alloc.c).
49 *
49 */ 50 */
50 51
51/* 52/*
@@ -78,7 +79,7 @@
78#define PG_checked 8 /* kill me in 2.5.<early>. */ 79#define PG_checked 8 /* kill me in 2.5.<early>. */
79#define PG_arch_1 9 80#define PG_arch_1 9
80#define PG_reserved 10 81#define PG_reserved 10
81#define PG_private 11 /* Has something at ->private */ 82#define PG_private 11 /* If pagecache, has fs-private data */
82 83
83#define PG_writeback 12 /* Page is under writeback */ 84#define PG_writeback 12 /* Page is under writeback */
84#define PG_nosave 13 /* Used for system suspend/resume */ 85#define PG_nosave 13 /* Used for system suspend/resume */
@@ -87,7 +88,7 @@
87 88
88#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ 89#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
89#define PG_reclaim 17 /* To be reclaimed asap */ 90#define PG_reclaim 17 /* To be reclaimed asap */
90#define PG_nosave_free 18 /* Free, should not be written */ 91#define PG_nosave_free 18 /* Used for system suspend/resume */
91#define PG_buddy 19 /* Page is free, on buddy lists */ 92#define PG_buddy 19 /* Page is free, on buddy lists */
92 93
93 94
@@ -103,134 +104,6 @@
103#endif 104#endif
104 105
105/* 106/*
106 * Global page accounting. One instance per CPU. Only unsigned longs are
107 * allowed.
108 *
109 * - Fields can be modified with xxx_page_state and xxx_page_state_zone at
110 * any time safely (which protects the instance from modification by
111 * interrupt.
112 * - The __xxx_page_state variants can be used safely when interrupts are
113 * disabled.
114 * - The __xxx_page_state variants can be used if the field is only
115 * modified from process context and protected from preemption, or only
116 * modified from interrupt context. In this case, the field should be
117 * commented here.
118 */
119struct page_state {
120 unsigned long nr_dirty; /* Dirty writeable pages */
121 unsigned long nr_writeback; /* Pages under writeback */
122 unsigned long nr_unstable; /* NFS unstable pages */
123 unsigned long nr_page_table_pages;/* Pages used for pagetables */
124 unsigned long nr_mapped; /* mapped into pagetables.
125 * only modified from process context */
126 unsigned long nr_slab; /* In slab */
127#define GET_PAGE_STATE_LAST nr_slab
128
129 /*
130 * The below are zeroed by get_page_state(). Use get_full_page_state()
131 * to add up all these.
132 */
133 unsigned long pgpgin; /* Disk reads */
134 unsigned long pgpgout; /* Disk writes */
135 unsigned long pswpin; /* swap reads */
136 unsigned long pswpout; /* swap writes */
137
138 unsigned long pgalloc_high; /* page allocations */
139 unsigned long pgalloc_normal;
140 unsigned long pgalloc_dma32;
141 unsigned long pgalloc_dma;
142
143 unsigned long pgfree; /* page freeings */
144 unsigned long pgactivate; /* pages moved inactive->active */
145 unsigned long pgdeactivate; /* pages moved active->inactive */
146
147 unsigned long pgfault; /* faults (major+minor) */
148 unsigned long pgmajfault; /* faults (major only) */
149
150 unsigned long pgrefill_high; /* inspected in refill_inactive_zone */
151 unsigned long pgrefill_normal;
152 unsigned long pgrefill_dma32;
153 unsigned long pgrefill_dma;
154
155 unsigned long pgsteal_high; /* total highmem pages reclaimed */
156 unsigned long pgsteal_normal;
157 unsigned long pgsteal_dma32;
158 unsigned long pgsteal_dma;
159
160 unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
161 unsigned long pgscan_kswapd_normal;
162 unsigned long pgscan_kswapd_dma32;
163 unsigned long pgscan_kswapd_dma;
164
165 unsigned long pgscan_direct_high;/* total highmem pages scanned */
166 unsigned long pgscan_direct_normal;
167 unsigned long pgscan_direct_dma32;
168 unsigned long pgscan_direct_dma;
169
170 unsigned long pginodesteal; /* pages reclaimed via inode freeing */
171 unsigned long slabs_scanned; /* slab objects scanned */
172 unsigned long kswapd_steal; /* pages reclaimed by kswapd */
173 unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
174 unsigned long pageoutrun; /* kswapd's calls to page reclaim */
175 unsigned long allocstall; /* direct reclaim calls */
176
177 unsigned long pgrotated; /* pages rotated to tail of the LRU */
178 unsigned long nr_bounce; /* pages for bounce buffers */
179};
180
181extern void get_page_state(struct page_state *ret);
182extern void get_page_state_node(struct page_state *ret, int node);
183extern void get_full_page_state(struct page_state *ret);
184extern unsigned long read_page_state_offset(unsigned long offset);
185extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
186extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
187
188#define read_page_state(member) \
189 read_page_state_offset(offsetof(struct page_state, member))
190
191#define mod_page_state(member, delta) \
192 mod_page_state_offset(offsetof(struct page_state, member), (delta))
193
194#define __mod_page_state(member, delta) \
195 __mod_page_state_offset(offsetof(struct page_state, member), (delta))
196
197#define inc_page_state(member) mod_page_state(member, 1UL)
198#define dec_page_state(member) mod_page_state(member, 0UL - 1)
199#define add_page_state(member,delta) mod_page_state(member, (delta))
200#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
201
202#define __inc_page_state(member) __mod_page_state(member, 1UL)
203#define __dec_page_state(member) __mod_page_state(member, 0UL - 1)
204#define __add_page_state(member,delta) __mod_page_state(member, (delta))
205#define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta))
206
207#define page_state(member) (*__page_state(offsetof(struct page_state, member)))
208
209#define state_zone_offset(zone, member) \
210({ \
211 unsigned offset; \
212 if (is_highmem(zone)) \
213 offset = offsetof(struct page_state, member##_high); \
214 else if (is_normal(zone)) \
215 offset = offsetof(struct page_state, member##_normal); \
216 else if (is_dma32(zone)) \
217 offset = offsetof(struct page_state, member##_dma32); \
218 else \
219 offset = offsetof(struct page_state, member##_dma); \
220 offset; \
221})
222
223#define __mod_page_state_zone(zone, member, delta) \
224 do { \
225 __mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
226 } while (0)
227
228#define mod_page_state_zone(zone, member, delta) \
229 do { \
230 mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
231 } while (0)
232
233/*
234 * Manipulation of page state flags 107 * Manipulation of page state flags
235 */ 108 */
236#define PageLocked(page) \ 109#define PageLocked(page) \
@@ -254,7 +127,13 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
254#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) 127#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
255 128
256#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) 129#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
257#ifndef SetPageUptodate 130#ifdef CONFIG_S390
131static inline void SetPageUptodate(struct page *page)
132{
133 if (!test_and_set_bit(PG_uptodate, &page->flags))
134 page_test_and_clear_dirty(page);
135}
136#else
258#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) 137#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
259#endif 138#endif
260#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) 139#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
@@ -306,7 +185,7 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
306 do { \ 185 do { \
307 if (!test_and_set_bit(PG_writeback, \ 186 if (!test_and_set_bit(PG_writeback, \
308 &(page)->flags)) \ 187 &(page)->flags)) \
309 inc_page_state(nr_writeback); \ 188 inc_zone_page_state(page, NR_WRITEBACK); \
310 } while (0) 189 } while (0)
311#define TestSetPageWriteback(page) \ 190#define TestSetPageWriteback(page) \
312 ({ \ 191 ({ \
@@ -314,14 +193,14 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
314 ret = test_and_set_bit(PG_writeback, \ 193 ret = test_and_set_bit(PG_writeback, \
315 &(page)->flags); \ 194 &(page)->flags); \
316 if (!ret) \ 195 if (!ret) \
317 inc_page_state(nr_writeback); \ 196 inc_zone_page_state(page, NR_WRITEBACK); \
318 ret; \ 197 ret; \
319 }) 198 })
320#define ClearPageWriteback(page) \ 199#define ClearPageWriteback(page) \
321 do { \ 200 do { \
322 if (test_and_clear_bit(PG_writeback, \ 201 if (test_and_clear_bit(PG_writeback, \
323 &(page)->flags)) \ 202 &(page)->flags)) \
324 dec_page_state(nr_writeback); \ 203 dec_zone_page_state(page, NR_WRITEBACK); \
325 } while (0) 204 } while (0)
326#define TestClearPageWriteback(page) \ 205#define TestClearPageWriteback(page) \
327 ({ \ 206 ({ \
@@ -329,7 +208,7 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
329 ret = test_and_clear_bit(PG_writeback, \ 208 ret = test_and_clear_bit(PG_writeback, \
330 &(page)->flags); \ 209 &(page)->flags); \
331 if (ret) \ 210 if (ret) \
332 dec_page_state(nr_writeback); \ 211 dec_zone_page_state(page, NR_WRITEBACK); \
333 ret; \ 212 ret; \
334 }) 213 })
335 214