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
  17 void 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 }