FlameGraph

Yes, they are made with: http://www.brendangregg.com/flamegraphs.html and https://github.com/brendangregg/FlameGraph Useful site if you are on to perf/eBPF/performance things with many examples and descriptions even for other uses as e.g. memory usage, disk usage (prefer heatmaps here but they are nice if you want to send someone a interactive view of their directory tree ...).

Courtesy of Brendan Gregg and his flamegraph.pl scripts: https://github.com/brendangregg/FlameGraph Normally, I use the generator included in async-profiler. It produces interactive HTML. But for this post, I used Brendan’s tool specifically to have a single, interactive SVG.

https://github.com/brendangregg/FlameGraph You record performance data with `perf`, then use the scripts there to turn it into a SVG.

If you want to "go low" in the operating system, you could write a Linux kernel module: https://sysprog21.github.io/lkmpg/ https://blog.sourcerer.io/writing-a-simple-linux-kernel-modu... If you want to "go low" in the way hardware works, you could try and write an interrupt handler on an embedded device. If you want to "go low" in how optimizations work in application development, you could try and implement microbenchmarks and look at flamegraphs. https://github.com/brendangregg/FlameGraph https://bheisler.github.io/criterion.rs/book/index.html

> Stack samples can be captured using Linux perf_events, FreeBSD pmcstat (hwpmc), DTrace, SystemTap, and many other profilers. See the stackcollapse-* converters https://github.com/brendangregg/FlameGraph

Historically brendangregg's since AIUI he basically invented flamegraphs https://www.brendangregg.com/flamegraphs.html So if you can make your tool eat whatever https://github.com/brendangregg/FlameGraph is fed with you're going to support a lot of existing tooling across OSes and languages.

URL in example says Go pprof so at least that. I wish it to be compatible with my go-to Ruby tools: https://github.com/ruby-prof/ruby-prof https://github.com/rbspy/rbspy thus replacing this one: https://github.com/brendangregg/FlameGraph

Small note: > In Rust, it is very easy to generate flamegraphs with `cargo flamegraph`. ... Also in pretty much every other language that can generate perf stacktraces, because this is just a wrapper around Brendan Gregg's FlameGraph visualizer: https://github.com/brendangregg/FlameGraph

When was the last time you needed to read assembly code to debug a kernel-level issue in FOSS software? There's a lot of software you can use to profile the entire kernel and userspace[0], or explore the stack trace[1] of your software. If you're not using those and instead debugging your software by counting SIMD calls in the Ghidra editor, you're wasting an unconscionable amount of time. People read through assembly to fix compiler issues, not to rationalize what the kernel is doing. You're right that this skill is still required for "perfect" optimization, but it's not really relevant when comparing kernels. [0] http://www.sysprof.com/ [1] https://github.com/brendangregg/FlameGraph

> [...] how Perf compares to vendor tools like vTune [...] ? Regarding the hardware events that Perf can capture on x86, it has pretty much all of them. So it should be equivalent to vTune for all practical purposes. The big difference is in the UI -- or absence thereof. Perf is a low-level tool and its output is mostly text files. There is a curses-based TUI for perf-report (and even gtk version, but it is essentially the same as the TUI, just using GTK2 widgets), but that's about it. By contrast, vTune comes with a heavy (electron-based?) GUI and is quite helpful in guiding beginners, with many graphs and explanations. Of course, one can (and is expected to) complement Perf with an assortment of tools that process its output for visualization. For example, the flamegraph [1] and heat map [2] tools described in the article. But also KDAB

it's a very painful process. debugger is my friend. Flamegraph is a bit useful https://github.com/brendangregg/FlameGraph

Another option is to generate a text file in the format expected by flamegraph. Especially useful when the data is hierarchical. https://github.com/brendangregg/FlameGraph Exemple for Java: https://github.com/pcdv/deps-flamegraph/blob/master/README.m...

Off topic: this is the same Brendan Gregg of flame charts fame [0][1]. It has solved my skin quite a few times when trying to figure out performance bottlenecks in Python apps (using pyflame[2] to capture data and FlameGraph[1] to convert it to displayable SVG). [0] http://www.brendangregg.com/flamegraphs.html [1] https://github.com/brendangregg/FlameGraph [2] https://github.com/uber-archive/pyflame

If you're talking about the flame graphs, they're a fairly common feature of modern profilers. The oldest implementation I know of is at https://github.com/brendangregg/FlameGraph.