Subject: Re: Limiting memory usage of bufcache?
To: Jukka Marin <jmarin@pyy.jmp.fi>
From: Matthias Buelow <mkb@mukappabeta.de>
List: netbsd-users
Date: 08/24/2001 02:48:24
Jukka Marin <jmarin@pyy.jmp.fi> writes:

>Well, the problem I'd like to fix somehow is that all my processes get
>paged out of RAM when I do lots of disk I/O.  After a nightly backup,

Urrrggh.  That sounds similarly broken like the WindowsNT behaviour we
have observed in an earlier version (dunno if it's still doing it) of
writing out its filecache pages to the swapfile.  If NetBSD is actually
paging out active pages to make room for the buffer cache, this is a
horribly serious bug and should be fixed ASAP!  The buffer cache must
always have a lower priority than user-space mapped pages and only use
completely unmapped memory pages which are unused otherwise (it shouldn't
even harrass the "inactive" pages of recently mapped but now unmapped
user pages.)

--mkb