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  * ./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
  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
  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
  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
  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
  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 }