Top broken in AMD64?

[Vivek Khera]

On Jun 8, 2005, at 5:12 PM, Andreas Klemm wrote:

> Even if I do a time make -j 8 buildworld I see only in rare cases
> display of up to 8 cc1 processes but mostly no display.
> as and ccp processes I see never.
>
> Its really strange and I'm not completely convinced that everything
> is right. If I remember right it was on exactly the same machine
> P3 1 GHz where this behaviour changed. I think it was between
> FreeBSD 4 and 5.
>

Think for a moment about how top must work: it has to take a poll of  
some system status every fixed interval.  if things are living  
shorter than that interval, you miss seeing them.  However, the OS  
can tell you how much CPU time was used during that interval and  
such.  ie, global counters kept by the kernel will show utilization,  
but the processes that used those resources won't show up unless you  
mange to look for them at just the right time.

Vivek Khera, Ph.D.
+1-301-869-4449 x806