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From:   Gianfranco Dutka <gianfranco.dutka@arista.com>
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Subject: Modifying isolcpus, nohz_full, and rcu_nocb kernel parameters at
 runtime
Message-Id: <76587DD3-2A77-41A3-9807-6AEE4398EBA6@arista.com>
Date:   Thu, 7 Dec 2023 10:07:13 -0500
Cc:     vincent.guittot@linaro.com
To:     linux-kernel@vger.kernel.org
Precedence: bulk

Good afternoon maintainers and subscribers to the lkml,=20

I'm a bit new to kernel development but I had a question with respect to =
the kernel parameters: isolcpus, nohz_full, and rcu_nocbs.=20

Basically the question is this, am I able to modify the three parameters =
I mentioned above at runtime after the kernel has already =
started/booted? Doing some reading online it seems that it=E2=80=99s not =
possible but I wanted to double check with the maintainers if there =
wasn=E2=80=99t some sort of change in the works that might make it =
possible. If not, what would be required to make the change after =
boot-time through some kind of patch or something like that? Would that =
be something that might be valuable upstream?

At the moment we are running an application that might see some benefit =
from being able to isolate cpus on the fly without having to reboot =
everything every time we want to modify the parameters mentioned above.=20=


Thanks,=20
Gianfranco=