From: Norbert Lange via lttng-dev <lttng-dev@lists.lttng.org>
To: lttng-dev <lttng-dev@lists.lttng.org>
Cc: david.aldrich.ntml@gmail.com
Subject: Re: A question regarding isolated cpus and software interrupts
Date: Tue, 17 Jun 2025 12:52:01 +0200 [thread overview]
Message-ID: <CADYdroMbjORvxZMZnNW=dZZsCvNhf9PEo9Bg2RYjN68ynwn-iA@mail.gmail.com> (raw)
Hello David,
You cant fully isolate a core in Linux, there are some timekeeping
functions that will always run (Linux needs some basic runtime
accounting).
The things you can do is avoiding IRQ handlers and "lazy" subsystems
that depend on background updates via timer or IPI. You already do
this via kernel parameters.
Maybe you can look at disabling membarrier too.
isolcpu just takes the core out of the scheduler, threads wont be
moved in or out automatically.
if you want to find out what causes the interrupts... use ftrace + kernelshark?
Norbert
next reply other threads:[~2025-06-17 10:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-17 10:52 Norbert Lange via lttng-dev [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-05-29 18:06 David Aldrich via lttng-dev
2025-05-30 14:49 ` Mathieu Desnoyers via lttng-dev
2025-05-30 15:00 ` David Aldrich via lttng-dev
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