[Bug 30557] Re: cpu idle time in /proc/stat wrong

[Brian Eaton]

I've put together a test program that demonstrates the
performance degradation introduced by this bug.
The attached tar ball contains information about the test program
and oprofile runs demonstrating the differences in
performance with max_cstate=1 and max_cstate=8.

I believe Ubuntu defect 50153 is a duplicate of 30557
because the symptoms and workarounds are the same.
However, 50153 is not reproducible in 2.6.15-23.  I first
noticed the problem in 2.6.15-25.  This is in conflict
with what some other reporters have experienced, with
30557 first appearing in 2.6.15-15.

The attached tar file contains the oprofile reports, the
test program, and a more detailed description of my tests.

-- 
cpu idle time in /proc/stat wrong
https://launchpad.net/bugs/30557