Subject: Re: UVM/other problems for desktop users in current?
To: George Michaelson <ggm@apnic.net>
From: Daniel Carosone <dan@geek.com.au>
List: current-users
Date: 12/18/2002 18:03:13
On Wed, Dec 18, 2002 at 04:33:44PM +1000, George Michaelson wrote:
> # atactl /dev/wd0 identify
> Model: IC25N010ATDA04-0, Rev: DACOA70A, Serial #:          170171J6499

That's a laptop disk, no?  The subject says desktops :)

However, laptops are certainly a good illustration of why you do
want to do "everything" on one machine.  Mine sure can't be dependent
on anything else.
 
> Command sets/features enabled:
>         write cache

Careful. See other thread.

However, with this on, if you're blocking for seeks it's almost
certainly reads, writes will return almost immediately unless
there's a whole lot and the disk's cache is full of them.
NEW_BUFQ_STRATEGY might even wind up worse for you. 

If these seeks are paging activity, then your apps will be stuck
until its done. I don't page out anons much or at all, so I can't
really comment on how the system feels in this case. Even file
reads will block most apps.

> [cc -pipe, tmp files, mfs]

Or in fact never happen at all, even without -pipe; if the tmp file
is unlinked again before the creation hits the disk all those
transactions can be unravelled.

--
Dan.