Subject: Re: ps hangs?
To: Blaz Zupan <>
From: Chris G Demetriou <Chris_G_Demetriou@BALVENIE.PDL.CS.CMU.EDU>
List: current-users
Date: 11/05/1995 20:12:50
> > Does anyone else see ps hang occasionally?  The system continues running fine,
> > ps uses lots of CPU time, and it just stops partway (about 2/3rds, for me,
> > most often, but seems random) through a listing.  You can ^C it and
> > everything is fine.
> Yes, I'm also seing this. As Jason Thorpe reports that he doesn't see it
> and he doesn't use Amigas this makes me think that this is maybe
> a NetBSD/amiga problem (I'm running NetBSD/amiga on an A2000 with IVS
> Vector/030).

I've seen it on x86 machines, but only when they're under very heavy
load.  It's likely due to the fact that the kernel data structures that
'ps' uses can change when ps is running, and ps doesn't (can't) get
them atomically.  Were ps more careful, it might be able to avoid the
infinite(?) loops, but that's not entirely clear.