Subject: Re: UVM/other problems for desktop users in current?
To: NetBSD-current Discussion List <current-users@netbsd.org>
From: Peter Seebach <seebs@plethora.net>
List: current-users
Date: 12/18/2002 00:20:17
In message <20021218055305.GH19317@deathmitten.example.org>, John Franklin writ
es:
>There's an issue here, but its not a couple of applications with 35M
>footprints on half-gig-plus RAM systems.

Indeed.  If I have 350MB of space used for files, and 100MB free, I'm
not running out of memory.

>I see similar problems with
>audio playback.  When there's some heavy swapping going on, realplayer
>will develop popping sounds or drop audio altogether.  Similar things
>happen with mplayer playing mp3s.  I've seen this with an dual P2/eap(4)
>based card, and a P3/clcs(4) based system.

Huh!  I have that problem with mpg123, although I can mitigate it by using a
2MB buffer ("mpg123 -b 2048").

>Without looking at the code, I would guess that certain IDE accesses
>lock out the rest of the system for way too long.  The result is cursors
>that don't move and audio that skips.  The problem may be limited to UVM
>interaction with IDE.  It may be more widespread throughout the
>interrupt handling code.  I don't know.

That's a likely guess, perhaps; it certainly seems to be a function of disk
access, not CPU or memory usage.

-s