Re: [BUG] How to get real-time priority using idle priority

[Brian Rogers <brian@xyzw.org>]

Ingo Molnar wrote:
> i've applied your fix to tip/sched/urgent and merged it into tip/master.
> Brian, you might want to test tip/master, as per:
>
>  http://people.redhat.com/mingo/tip.git/README
>
> which now has this fix included. Can you make it break?
>   
Yeah, I was able to trigger the same freeze again once on my desktop, 
but it appears to be harder to trigger now. I couldn't get my program to 
freeze the system, but one of the times I suspended then resumed BOINC, 
it happened.

While experimenting on my laptop, things got into a funny state where 
konsole froze, then gnome-terminal froze, so I just started launching 
xterms. pgrep and pidof would freeze and never terminate. ps axl froze 
after listing process 23681, which was a BOINC process. The next 
process, 23682, was another BOINC process. Going into /proc/23682 and 
running ls -l as root froze the shell. I figured out that ls -l exe was 
enough to freeze it. I couldn't shut down BOINC because process 23682 
wouldn't close, and kill -9 did nothing to it. top, which actually did 
work, showed that process just continuing to run with around 100% CPU 
time. I had to power cycle the system.

I'll try Mike's "more complete" patch on top of 2.6.29-rc1 and see what 
that does.