1 #include <linux/bootmem.h>
2 #include <linux/compiler.h>
4 #include <linux/init.h>
7 #include <linux/mmzone.h>
8 #include <linux/huge_mm.h>
9 #include <linux/proc_fs.h>
10 #include <linux/seq_file.h>
11 #include <linux/hugetlb.h>
12 #include <linux/memcontrol.h>
13 #include <linux/mmu_notifier.h>
14 #include <linux/page_idle.h>
15 #include <linux/kernel-page-flags.h>
16 #include <asm/uaccess.h>
19 #define KPMSIZE sizeof(u64)
20 #define KPMMASK (KPMSIZE - 1)
21 #define KPMBITS (KPMSIZE * BITS_PER_BYTE)
23 /* /proc/kpagecount - an array exposing page counts
25 * Each entry is a u64 representing the corresponding
26 * physical page count.
28 static ssize_t kpagecount_read(struct file *file, char __user *buf,
29 size_t count, loff_t *ppos)
31 u64 __user *out = (u64 __user *)buf;
33 unsigned long src = *ppos;
39 count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
40 if (src & KPMMASK || count & KPMMASK)
45 ppage = pfn_to_page(pfn);
48 if (!ppage || PageSlab(ppage))
51 pcount = page_mapcount(ppage);
53 if (put_user(pcount, out)) {
63 *ppos += (char __user *)out - buf;
65 ret = (char __user *)out - buf;
69 static const struct file_operations proc_kpagecount_operations = {
71 .read = kpagecount_read,
74 /* /proc/kpageflags - an array exposing page flags
76 * Each entry is a u64 representing the corresponding
77 * physical page flags.
80 static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
82 return ((kflags >> kbit) & 1) << ubit;
85 u64 stable_page_flags(struct page *page)
91 * pseudo flag: KPF_NOPAGE
92 * it differentiates a memory hole from a page with no flags
95 return 1 << KPF_NOPAGE;
101 * pseudo flags for the well known (anonymous) memory mapped pages
103 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
104 * simple test in page_mapped() is not enough.
106 if (!PageSlab(page) && page_mapped(page))
114 * compound pages: export both head/tail info
115 * they together define a compound page's start/end pos and order
118 u |= 1 << KPF_COMPOUND_HEAD;
120 u |= 1 << KPF_COMPOUND_TAIL;
124 * PageTransCompound can be true for non-huge compound pages (slab
125 * pages or pages allocated by drivers with __GFP_COMP) because it
126 * just checks PG_head/PG_tail, so we need to check PageLRU/PageAnon
127 * to make sure a given page is a thp, not a non-huge compound page.
129 else if (PageTransCompound(page)) {
130 struct page *head = compound_head(page);
132 if (PageLRU(head) || PageAnon(head))
134 else if (is_huge_zero_page(head)) {
135 u |= 1 << KPF_ZERO_PAGE;
138 } else if (is_zero_pfn(page_to_pfn(page)))
139 u |= 1 << KPF_ZERO_PAGE;
143 * Caveats on high order pages: page->_count will only be set
144 * -1 on the head page; SLUB/SLQB do the same for PG_slab;
145 * SLOB won't set PG_slab at all on compound pages.
150 if (PageBalloon(page))
151 u |= 1 << KPF_BALLOON;
153 if (page_is_idle(page))
156 u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
158 u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
160 u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
161 u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
162 u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
163 u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
165 u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
166 u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
167 u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
168 u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
170 u |= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
171 u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
173 u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
174 u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
176 #ifdef CONFIG_MEMORY_FAILURE
177 u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
180 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
181 u |= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
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);
194 static ssize_t kpageflags_read(struct file *file, char __user *buf,
195 size_t count, loff_t *ppos)
197 u64 __user *out = (u64 __user *)buf;
199 unsigned long src = *ppos;
204 count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
205 if (src & KPMMASK || count & KPMMASK)
210 ppage = pfn_to_page(pfn);
214 if (put_user(stable_page_flags(ppage), out)) {
224 *ppos += (char __user *)out - buf;
226 ret = (char __user *)out - buf;
230 static const struct file_operations proc_kpageflags_operations = {
232 .read = kpageflags_read,
236 static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
237 size_t count, loff_t *ppos)
239 u64 __user *out = (u64 __user *)buf;
241 unsigned long src = *ppos;
247 count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
248 if (src & KPMMASK || count & KPMMASK)
253 ppage = pfn_to_page(pfn);
258 ino = page_cgroup_ino(ppage);
262 if (put_user(ino, out)) {
272 *ppos += (char __user *)out - buf;
274 ret = (char __user *)out - buf;
278 static const struct file_operations proc_kpagecgroup_operations = {
280 .read = kpagecgroup_read,
282 #endif /* CONFIG_MEMCG */
284 static int __init proc_page_init(void)
286 proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
287 proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
289 proc_create("kpagecgroup", S_IRUSR, NULL, &proc_kpagecgroup_operations);
293 fs_initcall(proc_page_init);