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Date: Mon, 26 Mar 2012 19:03:42 +0200
From: Fabian Keil <freebsd-listen@fabiankeil.de>
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Subject: Re: NFSv3, ZFS, 10GE performance
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Bob Friesenhahn <bfriesen@simple.dallas.tx.us> wrote:

> On Mon, 26 Mar 2012, Sven Brandenburg wrote:
> >
> > Hopefully, readahead doesn't kill performance for smaller files.. :-)
>=20
> You are right to be concerned.  There are plenty of cases where=20
> read-ahead damages application performance.  Reading data which is=20
> never actually used is expensive.
>=20
> It would be useful if FreeBSD would support posix_fadvise() so that=20
> applications can specify the type of access they will use, and if this=20
> advice can be used by NFS and the filesystem layer to decide if=20
> read-ahead should be used, and how much.

posix_fadvise() is already available in FreeBSD 10.0-CURRENT.

Fabian

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