Re: 2.6.14-rc3-rt2

From: david singleton
Date: Wed Oct 05 2005 - 10:58:32 EST



On Oct 5, 2005, at 8:48 AM, Thomas Gleixner wrote:

On Wed, 2005-10-05 at 10:29 -0400, Steven Rostedt wrote:
Hmm, Ingo,

Do you know why time goes backwards when I run hackbench as a realtime
process? I added the output of start and stop and it does seem to go
backwards.

Thomas?

Yes. Thats happening. I moved the priority of softirq-timer above
hackbench priority and the problem goes away. I look into this further.

I had to set the threaded softirqs to real time priorities with the hi thread at 24,
the timer thread at 23, net_rx at 22, etc. I wanted their priorities just below the IRQ threads.

The problem was the timer thread. Other real time threads got in its way and held off timers.

And I had to make a note if any higher priority apps depended on timers that the timer
thread had to be boosted in priority to match that real time threads priority. It's like
the softirqd's timer thread needs priority inheritance.

David

tglx



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