meminfo详解.doc

Linux系统下/proc/meminfo详解 热3已有 8987 次阅读 2010-03-24 12:42 标签: Linux meminfo proc 详解 系统 /proc/meminfo Explained March 2003 Free, buffer, swap, dirty. What does it all mean? If you said, something to do with the Summer of 68, you may need a primer on meminfo. The entries in the /proc/meminfo can help explain whats going on with your memory usage, if you know how to read it. Example of cat /proc/meminfo: root: total: used: free: shared: buffers: cached: Mem: 1055760384 1041887232 0 100417536 711233536 Swap: 1077501952 8540160 1068961792 MemTotal: 1031016 kB MemFree: 13548 kB MemShared: 0 kB Buffers: 98064 kB Cached: 692320 kB SwapCached: 2244 kB Active: 563112 kB Inact_dirty: 309584 kB Inact_clean: 79508 kB Inact_target: 190440 kB HighTotal: 130992 kB HighFree: 1876 kB LowTotal: 900024 kB LowFree: 11672 kB SwapTotal: 1052248 kB SwapFree: 1043908 kB Committed_AS: 332340 kB The information comes in the form of both high-level and low-level statistics. At the top you see a quick summary of the most common values people would like to look at. Below you find the individual values we will discuss. First we will discuss the high-level statistics. High-Level Statistics MemTotal: Total usable ram (i.e. physical ram minus a few reserved bits and the kernel binary code) MemFree: Is sum of LowFree+HighFree (overall stat) MemShared: 0; is here for compat reasons but always zero. Buffers: Memory in buffer cache. mostly useless as metric nowadays Cached: Memory in the pagecache (diskcache) minus SwapCache SwapCache: Memory that once was swapped out, is swapped back in but still also is in the swapfile (if memory is needed it doesnt need to be swapped out AGAIN because it is already in the swapfile. This