Subject: Re: Jerky/frozen mouse under load
To: Jakub Misak <>
From: Steven M. Bellovin <>
List: netbsd-users
Date: 02/12/2005 23:06:08
In message <>, Jakub Misak writes:
>I was using NetBSD 1.6 before, which was good and smooth. But when I 
>switched to 2.0, I noticed that the mouse cursor tends to get much more 
>jerky or even frozen in X under heavy load, sometimes with extremely 
>long pauses. For example, when I unpacked pkgsrc.tgz in /usr, it was not 
>jerky - it was completely, 100% frozen for 10-15 seconds. Which means 
>that there was a 15 second pause when I couldn't move the mouse at all, 
>the whole system didn't respond at all.
>But even if the disc/CPU load is not so high, the mouse cursor very often 
>gets jerky during normal, regular tasks - for example when a page is 
>being loaded in a web browser, etc. 
>Why is 2.0 so much worse in this respect than 1.6 was (Linux on the same 
>PC is also much, much smoother)? Is there anything that can be done 
>about it?
>My system:
>Intel Celeron 2.4 GHz
>512 MB RAM
>XFree86 with nv driver

My guess is that you need to play with the VM sysctls, but I don't know 
what values to suggest.

		--Prof. Steven M. Bellovin,