Re: 4.2: CONFIG_NO_HZ_FULL_ALL effectively disabling non-boot CPUs

From: Meelis Roos
Date: Sun Oct 11 2015 - 03:26:57 EST


> > Short summary: turning on CONFIG_NO_HZ_FULL_ALL seems to disable all
> > non-boot CPUs for scheduler.

[...]

> This is expected and intended behavior. The whole point of
> CONFIG_NO_HZ_FULL_ALL is to keep everything off of the non-boot CPUs
> that is not explicitly placed there. Without CONFIG_NO_HZ_FULL_ALL,
> you can use the nohz_full boot parameter to select exactly which
> CPUs are to behave this way.

OK, thanks - disabled it on my desktops anyway now.

Perhaps the Kconfig description of it should explian the consequences
more clearly so other people do not stumble upon it like I did?

--
Meelis Roos (mroos@xxxxxxxx)
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