tools.git/enable-cycle-counter.district10, branch master kvm-run-kernel.sh and other utilities District10: enable the cycle counter on all processors 2010-11-09T22:08:28+00:00 Bjoern B. Brandenburg bbb@cs.unc.edu 2010-11-09T22:08:28+00:00 1081b867aec7a716f7a0c60ec5689487d12b4720 Do this by forcing a perf task on each CPU. 
Do this by forcing a perf task on each CPU.
add a script to enable the CCNT register on our MPCore box 2010-11-04T16:25:54+00:00 Bjoern B. Brandenburg bbb@cs.unc.edu 2010-11-04T16:25:54+00:00 5925a6033bef2cec578f5e4c6a0f774a9ff1ba4f The problem is that the CCNT register is not incremented unless specifically enabled on our particlar hardware. Just enabling the register during boot is insufficient since Linux's performance counter subsystem claims the hardware and messes with the control flags. We could either take over the hardware from Linux's performance counter framework, or trick Linux in turning on the cycle counter for us. The former approach require caryying ugly kernel patches, the latter is this simple script... 
The problem is that the CCNT register is not incremented unless
specifically enabled on our particlar hardware. Just enabling the
register during boot is insufficient since Linux's performance counter
subsystem claims the hardware and messes with the control flags.

We could either take over the hardware from Linux's performance
counter framework, or trick Linux in turning on the cycle counter for
us. The former approach require caryying ugly kernel patches, the
latter is this simple script...