Subject: Re: [PATCH v4 1/5] nohz_full: add support for "cpu_isolated" mode
To: Christoph Lameter <cl@linux.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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CC: Andy Lutomirski <luto@amacapital.net>,
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        Linux API <linux-api@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
From: Chris Metcalf <cmetcalf@ezchip.com>
Message-ID: <55B29E57.1070207@ezchip.com>
Date: Fri, 24 Jul 2015 16:21:43 -0400
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On 07/22/2015 04:02 PM, Christoph Lameter wrote:
> On Wed, 22 Jul 2015, Paul E. McKenney wrote:
>
>>>> Didn't Christoph Lameter fix this?  Or is this an additional problem?
>>> Well the vmstat update must realize first that there are no outstanding
>>> updates before switching itself off. So typically there is one extra tick.
>>> But we could add another function that will simply fold the differential
>>> immediately and turn the kworker task in the expectation that the
>>> processor will stay quiet.
>> Got it, thank you!
>>
>> 								Thanx, Paul
> Ok here is a function that quiets down the vmstat kworkers.

That's great - I will include this patch in my series then, and call it
as part of the "hard isolation" mode return to userspace.  Thanks!

-- 
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com

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