内核需要提示

/proc/sys/vm

Cache management with posix_fadvise()

New syscall in 2.6
– Cf. POSIX 1003.1, 2004 Edition
 Lets applications provide per-file aclearcase/" target="_blank" >ccess-pattern
hints to the kernel
– See man page for more info
 Features / options
– Random access
– Sequential access
– Force explicit readahead
– Explicit pagecache invalidation
• Use fsync() beforehand if the file is being written

原文转自：http://www.ltesting.net