Comment 2 for bug 782092

Martin, first, thanks for taking the time to file this bug report and help us make Ubuntu better.

This sounds more like a bug in the kernel's scheduling than openssh itself, I suspect anything trying to get
scheduled would have problems competing. Opening task against the kernel as well.

If you renice "prog.X" with

sudo renice `pidof prog.X` 5

Does the effect go away, or at least reduce significantly?

Also once you've ssh'd to the machine, do other programs run sluggishly?

Marking openssh task incomplete pending response (If it does go away with renice, and/or all programs that need CPU are sluggish, then this is not an openssh problem IMO).