pagemap.h revision 519be3a52434fbd94c8f395eb651faa22db3eeed 
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};
33
34/* Clears a memusage. */
35void pm_memusage_zero(pm_memusage_t *mu);
36/* Adds one memusage (a) to another (b). */
37void pm_memusage_add(pm_memusage_t *a, pm_memusage_t *b);
38
39typedef struct pm_kernel   pm_kernel_t;
40typedef struct pm_process  pm_process_t;
41typedef struct pm_map      pm_map_t;
42
43/* pm_kernel_t holds the state necessary to interface to the kernel's pagemap
44 * system on a global level. */
45struct pm_kernel {
46    int kpagecount_fd;
47    int kpageflags_fd;
48
49    int pagesize;
50};
51
52/* pm_process_t holds the state necessary to interface to a particular process'
53 * pagemap. */
54struct pm_process {
55    pm_kernel_t *ker;
56
57    pid_t pid;
58
59    pm_map_t **maps;
60    int num_maps;
61
62    int pagemap_fd;
63};
64
65/* pm_map_t holds the state necessary to access information about a particular
66 * mapping in a particular process. */
67struct pm_map {
68    pm_process_t *proc;
69
70    unsigned long start;
71    unsigned long end;
72    unsigned long offset;
73    int flags;
74
75    char *name;
76};
77
78/* Create a pm_kernel_t. */
79int pm_kernel_create(pm_kernel_t **ker_out);
80
81#define pm_kernel_pagesize(ker) ((ker)->pagesize)
82
83/* Get a list of probably-existing PIDs (returned through *pids_out).
84 * Length of the array (in sizeof(pid_t) units) is returned through *len.
85 * The array should be freed by the caller. */
86int pm_kernel_pids(pm_kernel_t *ker, pid_t **pids_out, size_t *len);
87
88/* Get the map count (from /proc/kpagecount) of a physical frame.
89 * The count is returned through *count_out. */
90int pm_kernel_count(pm_kernel_t *ker, unsigned long pfn, uint64_t *count_out);
91
92/* Get the page flags (from /proc/kpageflags) of a physical frame.
93 * The count is returned through *flags_out. */
94int pm_kernel_flags(pm_kernel_t *ker, unsigned long pfn, uint64_t *flags_out);
95
96#define PM_PAGE_LOCKED     (1 <<  0)
97#define PM_PAGE_ERROR      (1 <<  1)
98#define PM_PAGE_REFERENCED (1 <<  2)
99#define PM_PAGE_UPTODATE   (1 <<  3)
100#define PM_PAGE_DIRTY      (1 <<  4)
101#define PM_PAGE_LRU        (1 <<  5)
102#define PM_PAGE_ACTIVE     (1 <<  6)
103#define PM_PAGE_SLAB       (1 <<  7)
104#define PM_PAGE_WRITEBACK  (1 <<  8)
105#define PM_PAGE_RECLAIM    (1 <<  9)
106#define PM_PAGE_BUDDY      (1 << 10)
107
108/* Destroy a pm_kernel_t. */
109int pm_kernel_destroy(pm_kernel_t *ker);
110
111/* Get the PID of a pm_process_t. */
112#define pm_process_pid(proc) ((proc)->pid)
113
114/* Create a pm_process_t and returns it through *proc_out.
115 * Takes a pm_kernel_t, and the PID of the process. */
116int pm_process_create(pm_kernel_t *ker, pid_t pid, pm_process_t **proc_out);
117
118/* Get the total memory usage of a process and store in *usage_out. */
119int pm_process_usage(pm_process_t *proc, pm_memusage_t *usage_out);
120
121/* Get the working set of a process (if ws_out != NULL), and reset it
122 * (if reset != 0). */
123int pm_process_workingset(pm_process_t *proc, pm_memusage_t *ws_out, int reset);
124
125/* Get the PFNs corresponding to a range of virtual addresses.
126 * The array of PFNs is returned through *range_out, and the caller has the
127 * responsibility to free it. */
128int pm_process_pagemap_range(pm_process_t *proc,
129                             unsigned long low, unsigned long hi,
130                             uint64_t **range_out, size_t *len);
131
132#define _BITS(x, offset, bits) (((x) >> offset) & ((1LL << ((bits) + 1)) - 1))
133
134#define PM_PAGEMAP_PRESENT(x)     (_BITS(x, 63, 1))
135#define PM_PAGEMAP_SWAPPED(x)     (!_BITS(x, 62, 1))
136#define PM_PAGEMAP_SHIFT(x)       (_BITS(x, 55, 6))
137#define PM_PAGEMAP_PFN(x)         (_BITS(x, 0, 55))
138#define PM_PAGEMAP_SWAP_OFFSET(x) (_BITS(x, 5, 50))
139#define PM_PAGEMAP_SWAP_TYPE(x)   (_BITS(x, 0,  5))
140
141/* Get the maps in the virtual address space of this process.
142 * Returns an array of pointers to pm_map_t through *maps.
143 * The array should be freed by the caller, but the maps should not be
144 * modified or destroyed. */
145int pm_process_maps(pm_process_t *proc, pm_map_t ***maps_out, int *len);
146
147/* Destroy a pm_process_t. */
148int pm_process_destroy(pm_process_t *proc);
149
150/* Get the name, flags, start/end address, or offset of a map. */
151#define pm_map_name(map)   ((map)->name)
152#define pm_map_flags(map)  ((map)->flags)
153#define PM_MAP_READ  1
154#define PM_MAP_WRITE 2
155#define PM_MAP_EXEC  4
156#define pm_map_start(map)  ((map)->start)
157#define pm_map_end(map)    ((map)->end)
158#define pm_map_offset(map) ((map)->offset)
159
160/* Get the PFNs of the pages in the virtual address space of this map.
161 * Array of PFNs is returned through *pagemap_out, and should be freed by the
162 * caller. */
163int pm_map_pagemap(pm_map_t *map, uint64_t **pagemap_out, size_t *len);
164
165/* Get the memory usage of this map alone. */
166int pm_map_usage(pm_map_t *map, pm_memusage_t *usage_out);
167
168/* Get the working set of this map alone. */
169int pm_map_workingset(pm_map_t *map, pm_memusage_t *ws_out);
170
171#endif
172