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 * 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
  21struct block_list {
  22        char *txt;
  23        int len;
  24        int num;
  25};
  26
  27
  28static struct block_list *list;
  29static int list_size;
  30static int max_size;
  31
  32struct block_list *block_head;
  33
  34int 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
  47static 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
  54static 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
  61static 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
  87int 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}
 153