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Message-ID: <1329318679.2293.140.camel@twins>
Subject: Re: [v7 0/8] Reduce cross CPU IPI interference
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>,
        Frederic Weisbecker <fweisbec@gmail.com>, linux-kernel@vger.kernel.org,
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        Andi Kleen <andi@firstfloor.org>, Mel Gorman <mel@csn.ul.ie>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>, Avi Kivity <avi@redhat.com>,
        Michal Nazarewicz <mina86@mina86.com>,
        Kosaki Motohiro <kosaki.motohiro@gmail.com>,
        Milton Miller <miltonm@bga.com>
Date: Wed, 15 Feb 2012 16:11:19 +0100
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On Fri, 2012-02-10 at 22:24 +0200, Gilad Ben-Yossef wrote:
> I think the concept of giving the task some way to know if the tick is
> disabled or not is nice.
> Not sure the exact feature and surely not the interface are what we
> should adopt - maybe
> allow registering to receive a signal at the end of the tick when it
> is disabled an re-enabled? 

Fair enough, I indeed missed that property. And yes that makes sense. 

It might be a tad tricky to implement as things currently stand, because
AFAICR Frederic's stuff re-enables the tick on kernel entry (syscall)
things like signal delivery or a blocking wait for it might be 'fun'.

But I'll have to defer to Frederic, its been too long since I've seen
his patches to remember most details.