kern/104406: [ufs] Processes get stuck in "ufs" state underpersistent CPU load

[Kris Kennaway]

Rainer Hurling wrote:
> Looking into PR kern/104406 it seems, that this describes exactly what I 
> am experiencing on three of my systems over the last weeks. They are 
> running FreeBSD 8.0-CURRENT (known as 7.0-CURRENT not long ago ;-) ).

Actually it sounds nothing like it at all ;)

> On these machines I often observe hangings, sometimes only a few 
> seconds, on other times 20-30 seconds before input/output is back. This 
> seems to happen when more extensive disk usage is needed (portupgrade, 
> buildworld, browsing complicated websites etc.). During the hang even 
> xterm is not responding any more, other (diskless) applications like 
> xclock keep to continue. I have no panics, only UFS (and MSDOSFS) are 
> mounted, no NTFS. About two months ago none of my systems showed these 
> hangings.

Is your system swapping?  This is the usual cause of pauses during high 
application (actually memory) load.

Kris