Subject: Interactive performance in -current
To: None <>
From: None <>
List: tech-kern
Date: 10/24/2003 18:19:57
Hi all,

I've been noticing interactive performance degradation in recent current
(19 Oct, updating now to today) under somewhat heavy disk I/O (IDE).  Note
that the last commits WRT performance improvements are not in my actual
kernel, but should not improve things, AFAICT.

Some symptoms completely visible under X:
- The mouse does not move smoothly, the window manager (xfwm4) takes forever
  to switch desktops, terminal windows do not respond...
- The TV viewer (fxtv) does strange things (or at least bktr).  Periodically,
  a frame gets stalled and is overlapped over all the next ones, producing a
  very ugly effect.  It disappears after very few time, but happens again,
  almost continuously.  (and note that it is using overlayed video)
- XMMS stops playing (as commented in another message today).  Adjusting the
  volume, for example, lets it continue.

Some more notes: when this happens, if I run top, I can see that the CPU
interrupt state is very high, over 75% (dunno if this has something to do).
And this started happening recently; it was much better before.  I wonder if
this has something to do with all those changes done recently to the IDE

Ideas about what changed?


PS: Luckily, the system does not panic.

Julio M. Merino Vidal <>
The NetBSD Project -