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From: Terry Lambert <terry@lambert.org>
Message-Id: <199612310228.TAA01319@phaeton.artisoft.com>
Subject: Re: ipretard.c selective tcp/ip queues and throughput limiters
To: toor@dyson.iquest.net (John S. Dyson)
Date: Mon, 30 Dec 1996 19:28:47 -0700 (MST)
Cc: terry@lambert.org, julian@whistle.com, luigi@labinfo.iet.unipi.it,
        proff@iq.org, danny@panda.hilink.com.au, hackers@freebsd.org
In-Reply-To: <199612280319.WAA07203@dyson.iquest.net> from "John S. Dyson" at Dec 27, 96 10:19:01 pm
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> > For instance, for FS's, the VFS is well defined, but the VM interface
> > for doing actual disk I/O is not well abstracted at all.
>
> The VM code uses direct disk input when the filesystem allows it.  Otherwise,
> the filesystems can do VOP_READ operations as in normal UFS read write
> operations.  The vnode pageout uses VOP_WRITE operations.  Refer to
> vnode_pager (where the VM input output operations happen.)  I don't think
> that there are layering problems anymore (there were initially though.)

No, this particular issue isn't layering -- my favorite harp to play --
it's basically definition information that would be in a "file system
writer's guide"... if there were one.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.