LXR linux/tools/vm/page_owner

   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
  20struct block_list {
  21        char *txt;
  22        int len;
  23        int num;
  24};
  25
  26
  27static struct block_list *list;
  28static int list_size;
  29static int max_size;
  30
  31struct block_list *block_head;
  32
  33int 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
  48static 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
  55static 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
  62static 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
  88int 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        if (!list2) {
 136                printf("Out of memory\n");
 137                exit(1);
 138        }
 139
 140        printf("culling\n");
 141
 142        for (i = count = 0; i < list_size; i++) {
 143                if (count == 0 ||
 144                    strcmp(list2[count-1].txt, list[i].txt) != 0) {
 145                        list2[count++] = list[i];
 146                } else {
 147                        list2[count-1].num += list[i].num;
 148                }
 149        }
 150
 151        qsort(list2, count, sizeof(list[0]), compare_num);
 152
 153        for (i = 0; i < count; i++)
 154                fprintf(fout, "%d times:\n%s\n", list2[i].num, list2[i].txt);
 155
 156        return 0;
 157}
 158