On Monday 04 June 2007, Ingo Molnar wrote:

* Stephen Hemminger [off-list ref] wrote:

quoted

Yes, the following patch makes iperf work better than ever. But are
other broken applications going to have same problem. Sounds like the
old "who runs first" fork() problems.

this is the first such app and really, and even for this app: i've been
frequently running iperf on -rt kernels for _years_ and never noticed
how buggy its 'locking' code was, and that it would under some
circumstances use up the whole CPU on high-res timers.

I must admit I don't know much about that topic, but there is one thing I 
don't understand. Why is iperf (even if it's buggy) able to use up the whole 
cpu? I didn't run it as root but as my normal user so it should have limited 
rights. Shouldn't the linux scheduler distribute cpu time among all running 
processes?

Maxi