Re: [Lse-tech] [PATCH] break out numa scheduling config

[Rick L. <ric...@us...>]

Dave asked:

    Rick, have you been able to examine the SPECjbb200(tm)* problem and
    figure out whether it is really a balancing problem?

To answer your question directly, no, but I think as Andrew demonstrated
much of the work has alredy been done! :) Thanks Andrew.
    
    JBB really 
    shouldn't behave that way, but IMO, the scheduler should do its best should 
    that situation arise.  A change to wake_up helps this, since it's tied much 
    more closely to the rate of task activation. That's why the wake_up 
    modification works, and makes the NUMA config'd kernel run just as fast as 
    the non-NUMA config'd kernel

Here's my jbb-specific concern. From what I understand of jbb, once the
benchmark gets underway, there's a thread for each warehouse and it puts
its shoulder down and goes to work pretty intensively.  This behavior, though
suggests it's going in fits and starts.  Do we know which is correct?  That
is, does this focus on NUMA scheduling take the attention away from some
other aspect of the Specjbb benchmark which is just as important?  Is there
some sort of resource contention such that it stops and starts so often? What
is it stopping for?

Rick