Date: Mon, 10 Jan 2005 05:57:47 -0800 From: Kris Kennaway <kris@obsecurity.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: Scott Long <scottl@freebsd.org> Subject: Re: using mfs of size > 64Mb and system stability Message-ID: <20050110135747.GA44905@xor.obsecurity.org> In-Reply-To: <41247.1105351904@critter.freebsd.dk> References: <20050110100840.29845.qmail@web30301.mail.mud.yahoo.com> <41247.1105351904@critter.freebsd.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
--HlL+5n6rz5pIUxbD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 10, 2005 at 11:11:44AM +0100, Poul-Henning Kamp wrote: > In message <20050110100840.29845.qmail@web30301.mail.mud.yahoo.com>, Bara= th S w > rites: > >Initially, I didn't go for swap based fs as I felt > >that the memory occupied will be from the swap area. > >As you are saying that the allocation will be from > >buffer/cache, I will test swap-mfs. >=20 > malloc backing should not be used for large disks. >=20 > If you _truly_ want to have a large disk which is memory backed, > you should consider using the "preload" backing as this will withdraw > the memory entirely from the kernels use. >=20 > In general, the benefit from using RAM disks is much smaller than > most people realize. I've found that using a swap-backed disk substantially cuts back on disk accesses for my purposes (package building, where everything that hits disk will be deleted again in a few minutes). It appears to give a reasonable performance boost, which I'm still trying to measure. Unfortunately, swap-backed md under 6.x deadlocks under some conditions which are being investigated. Kris --HlL+5n6rz5pIUxbD Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (FreeBSD) iD8DBQFB4onbWry0BWjoQKURAoRMAKDe4IyajL2SoKlKR+PvJBMS3gaeWwCg8vm8 Gq8hke7Io29IXodGpr1RQn4= =FgCB -----END PGP SIGNATURE----- --HlL+5n6rz5pIUxbD--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050110135747.GA44905>