tools/vm/page_owner_sort.c

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