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authorWu Fengguang <fengguang.wu@intel.com>2009-06-16 18:32:24 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 22:47:38 -0400
commit177975495914efb372f7edee28ba9a0fdb754149 (patch)
treed26a09871ee7b250a5c96e323cc4d5245e35eeff /fs/proc/page.c
parented7ce0f1022942301776f93159c981b09382ddea (diff)
proc: export more page flags in /proc/kpageflags
Export all page flags faithfully in /proc/kpageflags. 11. KPF_MMAP (pseudo flag) memory mapped page 12. KPF_ANON (pseudo flag) memory mapped page (anonymous) 13. KPF_SWAPCACHE page is in swap cache 14. KPF_SWAPBACKED page is swap/RAM backed 15. KPF_COMPOUND_HEAD (*) 16. KPF_COMPOUND_TAIL (*) 17. KPF_HUGE hugeTLB pages 18. KPF_UNEVICTABLE page is in the unevictable LRU list 19. KPF_HWPOISON(TBD) hardware detected corruption 20. KPF_NOPAGE (pseudo flag) no page frame at the address 32-39. more obscure flags for kernel developers (*) For compound pages, exporting _both_ head/tail info enables users to tell where a compound page starts/ends, and its order. The accompanying page-types tool will handle the details like decoupling overloaded flags and hiding obscure flags to normal users. Thanks to KOSAKI and Andi for their valuable recommendations! Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/page.c')
-rw-r--r--fs/proc/page.c152
1 files changed, 120 insertions, 32 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c
index e73e911b7d0c..9d926bd279a4 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -72,19 +72,124 @@ static const struct file_operations proc_kpagecount_operations = {
72 72
73/* These macros are used to decouple internal flags from exported ones */ 73/* These macros are used to decouple internal flags from exported ones */
74 74
75#define KPF_LOCKED 0 75#define KPF_LOCKED 0
76#define KPF_ERROR 1 76#define KPF_ERROR 1
77#define KPF_REFERENCED 2 77#define KPF_REFERENCED 2
78#define KPF_UPTODATE 3 78#define KPF_UPTODATE 3
79#define KPF_DIRTY 4 79#define KPF_DIRTY 4
80#define KPF_LRU 5 80#define KPF_LRU 5
81#define KPF_ACTIVE 6 81#define KPF_ACTIVE 6
82#define KPF_SLAB 7 82#define KPF_SLAB 7
83#define KPF_WRITEBACK 8 83#define KPF_WRITEBACK 8
84#define KPF_RECLAIM 9 84#define KPF_RECLAIM 9
85#define KPF_BUDDY 10 85#define KPF_BUDDY 10
86 86
87#define kpf_copy_bit(flags, dstpos, srcpos) (((flags >> srcpos) & 1) << dstpos) 87/* 11-20: new additions in 2.6.31 */
88#define KPF_MMAP 11
89#define KPF_ANON 12
90#define KPF_SWAPCACHE 13
91#define KPF_SWAPBACKED 14
92#define KPF_COMPOUND_HEAD 15
93#define KPF_COMPOUND_TAIL 16
94#define KPF_HUGE 17
95#define KPF_UNEVICTABLE 18
96#define KPF_NOPAGE 20
97
98/* kernel hacking assistances
99 * WARNING: subject to change, never rely on them!
100 */
101#define KPF_RESERVED 32
102#define KPF_MLOCKED 33
103#define KPF_MAPPEDTODISK 34
104#define KPF_PRIVATE 35
105#define KPF_PRIVATE_2 36
106#define KPF_OWNER_PRIVATE 37
107#define KPF_ARCH 38
108#define KPF_UNCACHED 39
109
110static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
111{
112 return ((kflags >> kbit) & 1) << ubit;
113}
114
115static u64 get_uflags(struct page *page)
116{
117 u64 k;
118 u64 u;
119
120 /*
121 * pseudo flag: KPF_NOPAGE
122 * it differentiates a memory hole from a page with no flags
123 */
124 if (!page)
125 return 1 << KPF_NOPAGE;
126
127 k = page->flags;
128 u = 0;
129
130 /*
131 * pseudo flags for the well known (anonymous) memory mapped pages
132 *
133 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
134 * simple test in page_mapped() is not enough.
135 */
136 if (!PageSlab(page) && page_mapped(page))
137 u |= 1 << KPF_MMAP;
138 if (PageAnon(page))
139 u |= 1 << KPF_ANON;
140
141 /*
142 * compound pages: export both head/tail info
143 * they together define a compound page's start/end pos and order
144 */
145 if (PageHead(page))
146 u |= 1 << KPF_COMPOUND_HEAD;
147 if (PageTail(page))
148 u |= 1 << KPF_COMPOUND_TAIL;
149 if (PageHuge(page))
150 u |= 1 << KPF_HUGE;
151
152 u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
153
154 /*
155 * Caveats on high order pages:
156 * PG_buddy will only be set on the head page; SLUB/SLQB do the same
157 * for PG_slab; SLOB won't set PG_slab at all on compound pages.
158 */
159 u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
160 u |= kpf_copy_bit(k, KPF_BUDDY, PG_buddy);
161
162 u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
163 u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
164 u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
165 u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
166
167 u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
168 u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
169 u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
170 u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
171
172 u |= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
173 u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
174
175#ifdef CONFIG_UNEVICTABLE_LRU
176 u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
177 u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
178#endif
179
180#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
181 u |= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
182#endif
183
184 u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
185 u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
186 u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
187 u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
188 u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
189 u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
190
191 return u;
192};
88 193
89static ssize_t kpageflags_read(struct file *file, char __user *buf, 194static ssize_t kpageflags_read(struct file *file, char __user *buf,
90 size_t count, loff_t *ppos) 195 size_t count, loff_t *ppos)
@@ -94,7 +199,6 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
94 unsigned long src = *ppos; 199 unsigned long src = *ppos;
95 unsigned long pfn; 200 unsigned long pfn;
96 ssize_t ret = 0; 201 ssize_t ret = 0;
97 u64 kflags, uflags;
98 202
99 pfn = src / KPMSIZE; 203 pfn = src / KPMSIZE;
100 count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src); 204 count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
@@ -106,24 +210,8 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
106 ppage = pfn_to_page(pfn); 210 ppage = pfn_to_page(pfn);
107 else 211 else
108 ppage = NULL; 212 ppage = NULL;
109 if (!ppage) 213
110 kflags = 0; 214 if (put_user(get_uflags(ppage), out)) {
111 else
112 kflags = ppage->flags;
113
114 uflags = kpf_copy_bit(kflags, KPF_LOCKED, PG_locked) |
115 kpf_copy_bit(kflags, KPF_ERROR, PG_error) |
116 kpf_copy_bit(kflags, KPF_REFERENCED, PG_referenced) |
117 kpf_copy_bit(kflags, KPF_UPTODATE, PG_uptodate) |
118 kpf_copy_bit(kflags, KPF_DIRTY, PG_dirty) |
119 kpf_copy_bit(kflags, KPF_LRU, PG_lru) |
120 kpf_copy_bit(kflags, KPF_ACTIVE, PG_active) |
121 kpf_copy_bit(kflags, KPF_SLAB, PG_slab) |
122 kpf_copy_bit(kflags, KPF_WRITEBACK, PG_writeback) |
123 kpf_copy_bit(kflags, KPF_RECLAIM, PG_reclaim) |
124 kpf_copy_bit(kflags, KPF_BUDDY, PG_buddy);
125
126 if (put_user(uflags, out)) {
127 ret = -EFAULT; 215 ret = -EFAULT;
128 break; 216 break;
129 } 217 }