1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * User-space helper to sort the output of /sys/kernel/debug/page_owner
4 *
5 * Example use:
6 * cat /sys/kernel/debug/page_owner > page_owner_full.txt
7 * ./page_owner_sort page_owner_full.txt sorted_page_owner.txt
8 *
9 * See Documentation/vm/page_owner.rst
10 */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16 #include <fcntl.h>
17 #include <unistd.h>
18 #include <string.h>
19
20 struct block_list {
21 char *txt;
22 int len;
23 int num;
24 };
25
26
27 static struct block_list *list;
28 static int list_size;
29 static int max_size;
30
31 struct block_list *block_head;
32
read_block(char * buf,int buf_size,FILE * fin)33 int read_block(char *buf, int buf_size, FILE *fin)
34 {
35 char *curr = buf, *const buf_end = buf + buf_size;
36
37 while (buf_end - curr > 1 && fgets(curr, buf_end - curr, fin)) {
38 if (*curr == '\n') /* empty line */
39 return curr - buf;
40 if (!strncmp(curr, "PFN", 3))
41 continue;
42 curr += strlen(curr);
43 }
44
45 return -1; /* EOF or no space left in buf. */
46 }
47
compare_txt(const void * p1,const void * p2)48 static int compare_txt(const void *p1, const void *p2)
49 {
50 const struct block_list *l1 = p1, *l2 = p2;
51
52 return strcmp(l1->txt, l2->txt);
53 }
54
compare_num(const void * p1,const void * p2)55 static int compare_num(const void *p1, const void *p2)
56 {
57 const struct block_list *l1 = p1, *l2 = p2;
58
59 return l2->num - l1->num;
60 }
61
add_list(char * buf,int len)62 static void add_list(char *buf, int len)
63 {
64 if (list_size != 0 &&
65 len == list[list_size-1].len &&
66 memcmp(buf, list[list_size-1].txt, len) == 0) {
67 list[list_size-1].num++;
68 return;
69 }
70 if (list_size == max_size) {
71 printf("max_size too small??\n");
72 exit(1);
73 }
74 list[list_size].txt = malloc(len+1);
75 list[list_size].len = len;
76 list[list_size].num = 1;
77 memcpy(list[list_size].txt, buf, len);
78 list[list_size].txt[len] = 0;
79 list_size++;
80 if (list_size % 1000 == 0) {
81 printf("loaded %d\r", list_size);
82 fflush(stdout);
83 }
84 }
85
86 #define BUF_SIZE (128 * 1024)
87
main(int argc,char ** argv)88 int main(int argc, char **argv)
89 {
90 FILE *fin, *fout;
91 char *buf;
92 int ret, i, count;
93 struct block_list *list2;
94 struct stat st;
95
96 if (argc < 3) {
97 printf("Usage: ./program <input> <output>\n");
98 perror("open: ");
99 exit(1);
100 }
101
102 fin = fopen(argv[1], "r");
103 fout = fopen(argv[2], "w");
104 if (!fin || !fout) {
105 printf("Usage: ./program <input> <output>\n");
106 perror("open: ");
107 exit(1);
108 }
109
110 fstat(fileno(fin), &st);
111 max_size = st.st_size / 100; /* hack ... */
112
113 list = malloc(max_size * sizeof(*list));
114 buf = malloc(BUF_SIZE);
115 if (!list || !buf) {
116 printf("Out of memory\n");
117 exit(1);
118 }
119
120 for ( ; ; ) {
121 ret = read_block(buf, BUF_SIZE, fin);
122 if (ret < 0)
123 break;
124
125 add_list(buf, ret);
126 }
127
128 printf("loaded %d\n", list_size);
129
130 printf("sorting ....\n");
131
132 qsort(list, list_size, sizeof(list[0]), compare_txt);
133
134 list2 = malloc(sizeof(*list) * list_size);
135
136 printf("culling\n");
137
138 for (i = count = 0; i < list_size; i++) {
139 if (count == 0 ||
140 strcmp(list2[count-1].txt, list[i].txt) != 0) {
141 list2[count++] = list[i];
142 } else {
143 list2[count-1].num += list[i].num;
144 }
145 }
146
147 qsort(list2, count, sizeof(list[0]), compare_num);
148
149 for (i = 0; i < count; i++)
150 fprintf(fout, "%d times:\n%s\n", list2[i].num, list2[i].txt);
151
152 return 0;
153 }
154