Re: mmap vs. O_DIRECT

From: Alan Cox
Date: Wed Nov 10 2004 - 18:25:12 EST

On Mer, 2004-11-10 at 00:05, Bill Davidsen wrote:
> I have an application which does a lot of mmap to process its data. The
> huge waitio time makes me think that mmap isn't doing direct i/o even
> when things are alligned.

Make sure you are using MAP_SHARED in such cases so that the object you
have is the page cache object, also remember to use madvise

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