RTLA-OSNOISE(1)

🌸 RTLA-OSNOISE 🌸

okay bestie, so this is the manual page for rtla-osnoise, and it lives in the General Commands Manual section. It's giving "let me measure the operating system noise for you" and honestly? iconic. Let's go 💖

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✨ NAME ✨

rtla-osnoise — Measure the operating system noise. That's it. That's the whole job. 🎀

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🦋 SYNOPSIS 🦋

rtla osnoise [MODE] ...

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💜 DESCRIPTION 💜

So the rtla osnoise tool is basically the interface for the osnoise tracer. And the osnoise tracer? It dispatches a kernel thread per-cpu. These threads just read the time in a loop while preemption, softirq and IRQs are all enabled — which is the whole point, because that way every source of operating system noise can show up while they're doing their thing. 💅

The osnoise tracer's threads take note of the delta between each time read, along with an interference counter of all sources of interference. At the end of each period, the osnoise tracer displays a summary of the results. Periodt. ✨

The osnoise tracer outputs information in two ways:

• It periodically prints a summary of the noise of the operating system, including the counters of the occurrence of the source of interference.
• It also provides information for each noise via the osnoise: tracepoints.

The rtla osnoise top mode displays information about the periodic summary from the osnoise tracer. The rtla osnoise hist mode displays information about the noise using the osnoise: tracepoints. For further details, please refer to the respective man page. no cap 🫶

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🌈 MODES 🌈

• top — Prints the summary from osnoise tracer. 🌟
• hist — Prints a histogram of osnoise samples. 📊

If no MODE is given, the top mode is called, passing the arguments. she just defaults to being helpful, we love that 😌

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💅 OPTIONS 💅

• -h, --help — Display the help text. bestie behavior fr fr 💖

For other options, see the man page for the corresponding mode. go read those, they're right there 👑

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🎀 SEE ALSO 🎀

• rtla-osnoise-top(1)
• rtla-osnoise-hist(1)

Osnoise tracer <https://docs.kernel.org/trace/osnoise-tracer.html> 🔥

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👑 AUTHOR 👑

Written by Daniel Bristot de Oliveira < <bristot@kernel.org> > 💜

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😭 SIGINT BEHAVIOR 😭

okay this part is important so pay attention bestie, no skimming 🫶

• On the first SIGINT, RTLA exits after collecting all outstanding samples up to the point of receiving the signal. she's polite about it ✨
• When receiving more than one SIGINT, RTLA discards any outstanding samples, and exits while displaying only samples that have already been processed. 💀
• If SIGINT is received during RTLA cleanup, RTLA exits immediately via the default signal handler. 🏃‍♀️

Note: For the purpose of SIGINT behavior, the expiry of duration specified via the -d/--duration option is treated as equivalent to receiving a SIGINT. For example, a SIGINT received after duration expired but samples have not been processed yet will drop any outstanding samples. 🙈

Also note that when using the timerlat tool in BPF mode, samples are processed in-kernel; RTLA only copies them out to display them to the user. A second SIGINT does not affect in-kernel sample aggregation. 🧚

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⭐ EXIT STATUS ⭐

• 0 — Passed: the test did not hit the stop tracing condition ✅
• 1 — Error: invalid argument 🙃
• 2 — Failed: the test hit the stop tracing condition 💀
• 129 — Help: either user requested help or incorrect option was specified 🆘

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🐛 REPORTING BUGS 🐛

Report bugs to < <linux-kernel@vger.kernel.org> > and < <linux-trace-devel@vger.kernel.org> > — they wanna hear about it, fr fr 💌

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🌸 LICENSE 🌸

rtla is Free Software licensed under the GNU GPLv2. slay 💅

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🍓 COPYING 🍓

Copyright (C) 2021 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL). 📜

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and that's the whole page bestie!! 🌈✨ you made it to the end of RTLA-OSNOISE(1) — the General Commands Manual page, no date-stamp drama, just vibes. mwah, go measure some noise 💖🎀🦋