The Book of Xen

Profiling with Xen

Of course, there is one way of seeing shared resource use more precisely. We can profile the VM as it runs our application workload to get a clear idea of what it's doing and—with a Xen-aware profiler—how other domains are interfering with us.

Profiling refers to the practice of examining a specific application to see what it spends time doing. In particular, it can tell you whether an app is CPU or I/O limited, whether particular functions are inefficient, or whether performance problems are occurring outside of the app entirely, perhaps in the kernel.

Here, we'll discuss a sample setup with Xen and OProfile, using the kernel compile as a standard workload (and one that most Xen admins are likely to be familiar with).

Xenoprof ...