On Thu, Sep 10 2009, Con Kolivas wrote:
> > It probably just means that latt isn't a good measure of the problem.
> > Which isn't really too much of a surprise.
> 
> And that's a real shame because this was one of the first real good attempts 
> I've seen to actually measure the difference, and I thank you for your 
> efforts Jens. I believe the reason it's limited is because all you're 
> measuring is time from wakeup and the test app isn't actually doing any work. 
> The issue is more than just waking up as fast as possible, it's then doing 
> some meaningful amount of work within a reasonable time frame as well. What 
> the "meaningful amount of work" and "reasonable time frame" are, remains a 
> mystery, but I guess could be added on to this testing app.

Here's a quickie addition that adds some work to the threads. The
latency measure is now 'when did I wake up and complete my work'. The
default work is filling a buffer with pseudo random data and then
compressing it with zlib. Default is 64kb of data, can be adjusted with
-x. -x0 turns off work processing.

-- 
Jens Axboe