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From: Meelis Roos <mroos@linux.ee>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Linux Kernel list <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: 4.2: CONFIG_NO_HZ_FULL_ALL effectively disabling non-boot CPUs
Date: Sun, 11 Oct 2015 10:27:54 +0300 (EEST)	[thread overview]
Message-ID: <alpine.LRH.2.20.1510111026340.28155@math.ut.ee> (raw)
In-Reply-To: <20151010192439.GY3910@linux.vnet.ibm.com>

> > 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@linux.ee)

  reply	other threads:[~2015-10-11  7:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-10 19:14 4.2: CONFIG_NO_HZ_FULL_ALL effectively disabling non-boot CPUs Meelis Roos
2015-10-10 19:24 ` Paul E. McKenney
2015-10-11  7:27   ` Meelis Roos [this message]
2015-10-12  0:51   ` Frederic Weisbecker

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