Welkin小窩

/proc/meminfo

MemTotal — Total amount of physical RAM, in kilobytes.

MemFree — The amount of physical RAM, in kilobytes, left unused by the system.

Buffers — The amount of physical RAM, in kilobytes, used for file buffers.

Cached — The amount of physical RAM, in kilobytes, used as cache memory.

SwapCached — The amount of swap, in kilobytes, used as cache memory.

Active — The total amount of buffer or page cache memory, in kilobytes, that is in active use. This is memory that has been recently used and is usually not reclaimed for other purposes.

Inactive — The total amount of buffer or page cache memory, in kilobytes, that are free and available. This is memory that has not been recently used and can be reclaimed for other purposes.

HighTotal and HighFree — The total and free amount of memory, in kilobytes, that is not directly mapped into kernel space. The HighTotal value can vary based on the type of kernel used.

LowTotal and LowFree — The total and free amount of memory, in kilobytes, that is directly mapped into kernel space. The LowTotal value can vary based on the type of kernel used.

SwapTotal — The total amount of swap available, in kilobytes.

SwapFree — The total amount of swap free, in kilobytes.

Dirty — The total amount of memory, in kilobytes, waiting to be written back to the disk.

Writeback — The total amount of memory, in kilobytes, actively being written back to the disk.

Mapped — The total amount of memory, in kilobytes, which have been used to map devices, files, or libraries using the mmap command.

Slab — The total amount of memory, in kilobytes, used by the kernel to cache data structures for its own use.

Committed_AS — The total amount of memory, in kilobytes, estimated to complete the workload. This value represents the worst case scenario value, and also includes swap memory.

PageTables — The total amount of memory, in kilobytes, dedicated to the lowest page table level.

VMallocTotal — The total amount of memory, in kilobytes, of total allocated virtual address space.

VMallocUsed — The total amount of memory, in kilobytes, of used virtual address space.

VMallocChunk — The largest contiguous block of memory, in kilobytes, of available virtual address space.

HugePages_Total — The total number of hugepages for the system. The number is derived by dividing Hugepagesize by the megabytes set aside for hugepages specified in /proc/sys/vm/hugetlb_pool. This statistic only appears on the x86, Itanium, and AMD64 architectures.

HugePages_Free — The total number of hugepages available for the system. This statistic only appears on the x86, Itanium, and AMD64 architectures.

Hugepagesize — The size for each hugepages unit in kilobytes. By default, the value is 4096 KB on uniprocessor kernels for 32 bit architectures. For SMP, hugemem kernels, and AMD64, the default is 2048 KB. For Itanium architectures, the default is 262144 KB. This statistic only appears on the x86, Itanium, and AMD64 architectures.




此處由 Documentation/filesystems/proc.txt 轉錄
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Provides information about distribution and utilization of memory.
This varies by architecture and compile options.
The following is from a 16GB PIII, which has highmem enabled.
You may not have all of these fields.

MemTotal: 所有可用 RAM 大小。(即實體記憶體減去一些預留位和內核的二進制代碼大小)
MemFree: LowFree 與 HighFree 的總和。
Buffers: 用來給設備做緩衝大小。(只記錄文件系統的 metadata 以及 tracking in-flight pages，就是說 buffers 是用來儲存目錄裏面有什麽內容，權限等等。)
Cached: 用來給文件做緩衝大小。(直接用來記憶我們打開的文件)(它不包括 SwapCached)
SwapCached: 已經被交換出來的記憶體，但仍然被存放在 swapfile 中。用來在需要的時候很快的被替換而不需要再次打開I/O裝置。
Active: 最近經常被使用的記憶體，除非非常必要否則不會被移作他用.
Inactive: 最近不經常被使用的記憶體，非常用可能被用於其他途徑.
HighTotal:
HighFree: 高位記憶體是指所有在860MB以上的內存空間，該區域主要用於用戶空間的程式或者是緩衝頁面。作業系統必須使用不同的方法存取該段記憶體，因此它比低位記憶體要慢一些。
LowTotal:
LowFree: 低位可以達到高位記憶體一樣的作用，而且它還能夠被作業系統用來記錄一些自己的資料結構。
SwapTotal: 交換空間的總和
SwapFree: 從RAM中被替換出暫時存在硬碟上的空間大小
Dirty: 等待被寫回到硬碟的記憶體大小。
Writeback: 正在被寫回到硬碟的記憶體大小。
Mapped: 影射文件的大小。
Slab: 作業系統資料結構緩衝
VmallocTotal: vmalloc記憶體大小
VmallocUsed: 已經被使用的虛擬記憶體大小。
VmallocChunk: largest contigious block of vmalloc area which is free