/ proc/meminfo中的条目

Question

我可以理解/ proc/meminfo中包含的大部分信息,如总内存,缓冲区,缓存等.你能告诉我,下面列出的那些不太明显的是什么意思？

• AnonPages
• 映射
• 板
• NFS_Unstable
• 弹跳
• VmallocTotal
• VmallocUsed
• VmallocChunk

如果有人想知道,我在谈论linux命令cat/proc/meminfo的输出

Answer 1

此信息的规范来源是/usr/src/linux/Documentation/filesystems/proc.txt.特别,

   AnonPages: Non-file backed pages mapped into userspace page tables
      Mapped: files which have been mmaped, such as libraries
        Slab: in-kernel data structures cache
NFS_Unstable: NFS pages sent to the server, but not yet committed to stable
        storage
      Bounce: Memory used for block device "bounce buffers"
VmallocTotal: total size of vmalloc memory area
 VmallocUsed: amount of vmalloc area which is used
VmallocChunk: largest contigious block of vmalloc area which is free

Answer 2

我的理解如下.
我同意这些数字很难理解并显示出不一致的价值观.

• MemTotal

  = MemFree + Active + Inactive + Slab + PageTables + VmallocUsed + X
  (X : alloc_pages() (get_free_pages(), etc))
  

  但最近内核的vmallocused值可能是错误的.这是因为它计算VM_xxx区域,如VM_IOREMAP,VM_MAP,...而不是VM_ALLOC区域.

  VM_IOREMAP区域可以映射内存,这可以在内核的内存管理之外,因此上面的公式可能不精确或完全错误.

  你可以这样做:

  • 检查/ proc/vmallocinfo以整理所有条目并自行过滤,
  • 修改fs/proc/mmu.c:get_vmalloc_info()仅在if(vma-> flags&VM_ALLOC)时计算区域

• 有效+无效

   = Buffers + Cached + SwapCached + AnonPages
  

• AnonPages

   = /proc/*/task/*/smaps anonymous area all sum
   (anonymous: no name|[heap]|/dev/zero|/dev/shm/*|[stack])
  

  虽然我无法匹配这些数字.如果您有任何线索,请看这里并帮助我.

• 总PageCache

   = Buffers + Cached + SwapCached
  

• 板

   = SReclaimable + SUnreclaim