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