Subject: Re: performance slowdown after longish uptime
To: Mark Davies <mark@MCS.VUW.AC.NZ>
From: Richard Earnshaw <>
List: current-users
Date: 08/25/2000 10:22:13
> We have a problem using current that after a machine has been running for 1 to 
> 2 weeks it gets into a state where performance goes to pot with large amounts 
> of disk activity accompanying any operation.
> eg starting netscape takes over a minute rather than the normal 15 seconds or 
> so.  This persists until you reboot the machine.
> This is with 1.5A on i386 but the problem has been there with any current 
> version we've run back through 1.4P and possibly earlier.  I had been 
> assuming that it was somehow softdep related so upgraded to a new current each
> time significant bugfixes to the softdep code were announced, then waited a
> couple of weeks to see if the problem was still there.  Thinking about it I'm 
> not sure how it could be softdep related as it happens when all you are doing 
> is reading from a filesystem that is not mounted with softdep.
> So can anyone suggest what I can do to try and pin this down?

Well I saw a problem like this a while back (it started about the time 
that softdep was integrated).  The symptoms were similar to those you 
describe -- heavy disk activity after the machine had been up for about a 

But that problem was fixed somewhere around 1.4X by Chuck based on my PR.  
See kern/9792 for details.