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Subject: Re: [PATCH] sched/rt: don't try to balance rt_runtime when it is
 futile
From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: paulmck@linux.vnet.ibm.com
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>,
        linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
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        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 15 May 2014 05:18:51 +0200
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On Wed, 2014-05-14 at 08:44 -0700, Paul E. McKenney wrote:

> In practice, not sure how much testing CONFIG_NO_HZ_FULL=y has received
> for -rt kernels in production environments.

I took 3.14-rt out for a quick spin on my 64 core box, it didn't work at
all with 60 cores isolated.  I didn't have time to rummage, but it looks
like there are still bugs to squash. 

Biggest problem with CONFIG_NO_HZ_FULL is the price tag.  It just raped
fast mover performance last time I measured.

-Mike