Hotspot can now be used to analyze off-CPU time, i.e. time where your application is switched out and not running. This can be used to find heavy lock contention, synchronous I/O wait time and more. The record page offers a simple check box to enable this feature. If you run perf record directly from the command line and only use hotspot to visualize the results, make sure to pass the following flags:
perf record --call-graph dwarf -e cycles -e sched:sched_switch --switch-events --sample-cpu ...
The record page in hotspot now also has the capability to elevate your user permissions temporarily using kdesu, to allow recording of e.g. off-CPU data even as non-root.
The v1.2.0 release also adds quite a few bug fixes, performance improvements and also some other new features. Notable is the addition of a per-CPU core event timeline, which depends on the --sample-cpu flag being passed to perf record. Furthermore, you can now filter events by symbols: Right click on any of the data tables or views and then select the 'filter in/out by symbol` action.