LXR linux/fs/proc/mmu.c

   1/* mmu.c: mmu memory info files
   2 *
   3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11#include <linux/spinlock.h>
  12#include <linux/vmalloc.h>
  13#include <linux/highmem.h>
  14#include <asm/pgtable.h>
  15#include "internal.h"
  16
  17void get_vmalloc_info(struct vmalloc_info *vmi)
  18{
  19        struct vm_struct *vma;
  20        unsigned long free_area_size;
  21        unsigned long prev_end;
  22
  23        vmi->used = 0;
  24
  25        if (!vmlist) {
  26                vmi->largest_chunk = VMALLOC_TOTAL;
  27        }
  28        else {
  29                vmi->largest_chunk = 0;
  30
  31                prev_end = VMALLOC_START;
  32
  33                read_lock(&vmlist_lock);
  34
  35                for (vma = vmlist; vma; vma = vma->next) {
  36                        unsigned long addr = (unsigned long) vma->addr;
  37
  38                        /*
  39                         * Some archs keep another range for modules in vmlist
  40                         */
  41                        if (addr < VMALLOC_START)
  42                                continue;
  43                        if (addr >= VMALLOC_END)
  44                                break;
  45
  46                        vmi->used += vma->size;
  47
  48                        free_area_size = addr - prev_end;
  49                        if (vmi->largest_chunk < free_area_size)
  50                                vmi->largest_chunk = free_area_size;
  51
  52                        prev_end = vma->size + addr;
  53                }
  54
  55                if (VMALLOC_END - prev_end > vmi->largest_chunk)
  56                        vmi->largest_chunk = VMALLOC_END - prev_end;
  57
  58                read_unlock(&vmlist_lock);
  59        }
  60}
  61