Status and Challenges for the Perfmon Monitoring Interface

In the first part of the session, we summarize the changes and report on the status of the integration with the mainline kernel. In a second part, we present two challenges facing the interface. The first is how to allow multiple conflicting tools to share the performance counters, i.e., how to allow a system-wide tool to run concurrently with a per-thread tool or how to share the counters between perfmon and the NMI watchdog. The second challenge is how to ensure continuity of service once the Linux kernel runs in a virtualized environment such as KVM or Xen.