pagemap.h revision 931563e96d9ff65d7d2a4642c8f26fb19e47be47 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef _PAGEMAP_PAGEMAP_H
18#define _PAGEMAP_PAGEMAP_H
19
20#include <stdint.h>
21#include <stdio.h>
22#include <sys/types.h>
23
24typedef struct pm_memusage pm_memusage_t;
25
26/* Holds the various metrics for memory usage of a process or a mapping. */
27struct pm_memusage {
28    size_t vss;
29    size_t rss;
30    size_t pss;
31    size_t uss;
32    size_t swap;
33};
34
35/* Clears a memusage. */
36void pm_memusage_zero(pm_memusage_t *mu);
37/* Adds one memusage (a) to another (b). */
38void pm_memusage_add(pm_memusage_t *a, pm_memusage_t *b);
39
40typedef struct pm_kernel   pm_kernel_t;
41typedef struct pm_process  pm_process_t;
42typedef struct pm_map      pm_map_t;
43
44/* pm_kernel_t holds the state necessary to interface to the kernel's pagemap
45 * system on a global level. */
46struct pm_kernel {
47    int kpagecount_fd;
48    int kpageflags_fd;
49
50    int pagesize;
51};
52
53/* pm_process_t holds the state necessary to interface to a particular process'
54 * pagemap. */
55struct pm_process {
56    pm_kernel_t *ker;
57
58    pid_t pid;
59
60    pm_map_t **maps;
61    int num_maps;
62
63    int pagemap_fd;
64};
65
66/* pm_map_t holds the state necessary to access information about a particular
67 * mapping in a particular process. */
68struct pm_map {
69    pm_process_t *proc;
70
71    unsigned long start;
72    unsigned long end;
73    unsigned long offset;
74    int flags;
75
76    char *name;
77};
78
79/* Create a pm_kernel_t. */
80int pm_kernel_create(pm_kernel_t **ker_out);
81
82#define pm_kernel_pagesize(ker) ((ker)->pagesize)
83
84/* Get a list of probably-existing PIDs (returned through *pids_out).
85 * Length of the array (in sizeof(pid_t) units) is returned through *len.
86 * The array should be freed by the caller. */
87int pm_kernel_pids(pm_kernel_t *ker, pid_t **pids_out, size_t *len);
88
89/* Get the map count (from /proc/kpagecount) of a physical frame.
90 * The count is returned through *count_out. */
91int pm_kernel_count(pm_kernel_t *ker, unsigned long pfn, uint64_t *count_out);
92
93/* Get the page flags (from /proc/kpageflags) of a physical frame.
94 * The count is returned through *flags_out. */
95int pm_kernel_flags(pm_kernel_t *ker, unsigned long pfn, uint64_t *flags_out);
96
97#define PM_PAGE_LOCKED     (1 <<  0)
98#define PM_PAGE_ERROR      (1 <<  1)
99#define PM_PAGE_REFERENCED (1 <<  2)
100#define PM_PAGE_UPTODATE   (1 <<  3)
101#define PM_PAGE_DIRTY      (1 <<  4)
102#define PM_PAGE_LRU        (1 <<  5)
103#define PM_PAGE_ACTIVE     (1 <<  6)
104#define PM_PAGE_SLAB       (1 <<  7)
105#define PM_PAGE_WRITEBACK  (1 <<  8)
106#define PM_PAGE_RECLAIM    (1 <<  9)
107#define PM_PAGE_BUDDY      (1 << 10)
108
109/* for kernels >= 2.6.31 */
110#define PM_PAGE_MMAP          (1 << 11)
111#define PM_PAGE_ANON          (1 << 12)
112#define PM_PAGE_SWAPCACHE     (1 << 13)
113#define PM_PAGE_SWAPBACKED    (1 << 14)
114#define PM_PAGE_COMPOUND_HEAD (1 << 15)
115#define PM_PAGE_COMPOUND_TAIL (1 << 16)
116#define PM_PAGE_HUGE          (1 << 17)
117#define PM_PAGE_UNEVICTABLE   (1 << 18)
118#define PM_PAGE_HWPOISON      (1 << 19)
119#define PM_PAGE_NOPAGE        (1 << 20)
120
121/* for kernels >= 2.6.32 */
122#define PM_PAGE_KSM           (1 << 21)
123
124/* for kernels >= 3.4 */
125#define PM_PAGE_THP           (1 << 22)
126
127/* Destroy a pm_kernel_t. */
128int pm_kernel_destroy(pm_kernel_t *ker);
129
130/* Get the PID of a pm_process_t. */
131#define pm_process_pid(proc) ((proc)->pid)
132
133/* Create a pm_process_t and returns it through *proc_out.
134 * Takes a pm_kernel_t, and the PID of the process. */
135int pm_process_create(pm_kernel_t *ker, pid_t pid, pm_process_t **proc_out);
136
137/* Get the total memory usage of a process and store in *usage_out. */
138int pm_process_usage(pm_process_t *proc, pm_memusage_t *usage_out);
139
140/* Get the total memory usage of a process and store in *usage_out, only
141 * counting pages with specified flags. */
142int pm_process_usage_flags(pm_process_t *proc, pm_memusage_t *usage_out,
143                        uint64_t flags_mask, uint64_t required_flags);
144
145/* Get the working set of a process (if ws_out != NULL), and reset it
146 * (if reset != 0). */
147int pm_process_workingset(pm_process_t *proc, pm_memusage_t *ws_out, int reset);
148
149/* Get the PFNs corresponding to a range of virtual addresses.
150 * The array of PFNs is returned through *range_out, and the caller has the
151 * responsibility to free it. */
152int pm_process_pagemap_range(pm_process_t *proc,
153                             unsigned long low, unsigned long hi,
154                             uint64_t **range_out, size_t *len);
155
156#define _BITS(x, offset, bits) (((x) >> offset) & ((1LL << (bits)) - 1))
157
158#define PM_PAGEMAP_PRESENT(x)     (_BITS(x, 63, 1))
159#define PM_PAGEMAP_SWAPPED(x)     (_BITS(x, 62, 1))
160#define PM_PAGEMAP_SHIFT(x)       (_BITS(x, 55, 6))
161#define PM_PAGEMAP_PFN(x)         (_BITS(x, 0, 55))
162#define PM_PAGEMAP_SWAP_OFFSET(x) (_BITS(x, 5, 50))
163#define PM_PAGEMAP_SWAP_TYPE(x)   (_BITS(x, 0,  5))
164
165/* Get the maps in the virtual address space of this process.
166 * Returns an array of pointers to pm_map_t through *maps.
167 * The array should be freed by the caller, but the maps should not be
168 * modified or destroyed. */
169int pm_process_maps(pm_process_t *proc, pm_map_t ***maps_out, size_t *len);
170
171/* Destroy a pm_process_t. */
172int pm_process_destroy(pm_process_t *proc);
173
174/* Get the name, flags, start/end address, or offset of a map. */
175#define pm_map_name(map)   ((map)->name)
176#define pm_map_flags(map)  ((map)->flags)
177#define PM_MAP_READ  1
178#define PM_MAP_WRITE 2
179#define PM_MAP_EXEC  4
180#define PM_MAP_PERMISSIONS (PM_MAP_READ | PM_MAP_WRITE | PM_MAP_EXEC)
181#define pm_map_start(map)  ((map)->start)
182#define pm_map_end(map)    ((map)->end)
183#define pm_map_offset(map) ((map)->offset)
184
185/* Get the PFNs of the pages in the virtual address space of this map.
186 * Array of PFNs is returned through *pagemap_out, and should be freed by the
187 * caller. */
188int pm_map_pagemap(pm_map_t *map, uint64_t **pagemap_out, size_t *len);
189
190/* Get the memory usage of this map alone. */
191int pm_map_usage(pm_map_t *map, pm_memusage_t *usage_out);
192
193/* Get the memory usage of this map alone, only counting pages with specified
194 * flags. */
195int pm_map_usage_flags(pm_map_t *map, pm_memusage_t *usage_out,
196                        uint64_t flags_mask, uint64_t required_flags);
197
198/* Get the working set of this map alone. */
199int pm_map_workingset(pm_map_t *map, pm_memusage_t *ws_out);
200
201#endif
202