Subject: Re: Is O_DIRECT useless on NetBSD?
To: None <tech-kern@NetBSD.org>
From: Roland Illig <roland.illig@gmx.de>
List: tech-kern
Date: 11/21/2007 15:11:39
Roland Illig wrote:
> Hi,
>
> I have written a little archiver program, since both pax and tar cannot
> create files larger than 4 GB. :(
This part of the problem is solved. Now back to the main problem, which
should be at least as interesting as bashing filesystems:
> Since I expect the program to not read any data twice, I added the
> O_DIRECT flag to all open(2) calls. But top(1) still tells me that most
> of my RAM is occupied by "FILE", and only about 1 megabyte is "Free".
>
> All the involved filesystems are ffs. So did I understand O_DIRECT
> wrong? Or is it at all impossible to disable the kernel cache for file
> data?
Roland