Hotspot

The Linux perf GUI for C, C++ and Rust performance analysis

Hotspot is a standalone, user-friendly GUI for Linux perf. It works with any natively compiled code, including C, C++ and Rust, and with mixed-language applications. Load or record a perf.data file and Hotspot turns it into interactive flame graphs, caller/callee views and timelines, so you can easily find bottlenecks in your application.

Hotspot also fully supports Qt 6 and KF6, while keeping compatibility with Qt 5 and KF5. Check out the latest developments in the latest changelog on GitHub.

Why Hotspot

Compared to perf report, Hotspot has the following advantages:

The built-in flamegraph - easily the most important feature of hotspot - allows you to find optimization opportunities even in large code bases.
The interactive GUI with tooltips makes it easy to analyze data in different ways.
Its functionality is intuitive - no need to remember the magic invocation perf report -g srcline -s dso,sym,srcline --inline.
It has the ability to display multiple events in one view, [as shown in the screenshots below].
The top-down, bottom-up and caller/callee aggregations make understanding the results easier than the default aggregation of perf report.
Full support for cross-machine analysis as required for embedded development - check out the details in the 'readme' file.

Overview of Languages supported by Hotspot

Language	What you get
Language	Full support. Symbols, inlined functions, source lines and disassembly.
C++	Full support. Demangled names, templates and inlining. The regex filter helps in large codebases.
Rust	Full support, including Rust demangling and the v0 mangling scheme that is now the default since Rust 1.97. Generic instantiations stay readable in the flame graph.
Mixed C++/Rust (e.g., CXX-Qt)	One profile, one flame graph, both languages. Follow a call from QML/C++ into your Rust crate and back.
Other native languages	Anything perf can sample