Status and Challenges for the Perfmon Monitoring InterfaceStephane Eranian (firstname.lastname@example.org)
In one year, the perfmon interface and its implementation have evolved. There are new features and support for more processors, such as Intel Core 2 Duo. The code has been reviewed on LKML and many changes have been made to fit the Linux model and improve the code quality.
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.