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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Andi Kleen <andi@firstfloor.org>
Subject: Re: loaded router, excessive getnstimeofday in oprofile
Date: Thu, 28 Aug 2008 10:45:03 +1000
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Cc: David Miller <davem@davemloft.net>, rick.jones2@hp.com,
       johnpol@2ka.mipt.ru, dada1@cosmosbay.com, denys@visp.net.lb,
       netdev@vger.kernel.org, linux-kernel@vger.kernel.org
References: <87vdxmr53f.fsf@basil.nowhere.org> <20080827.151824.14173512.davem@davemloft.net> <20080827223952.GE26610@one.firstfloor.org>
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On Thursday 28 August 2008 08:39, Andi Kleen wrote:
> On Wed, Aug 27, 2008 at 03:18:24PM -0700, David Miller wrote:
> > From: Andi Kleen <andi@firstfloor.org>
> > Date: Wed, 27 Aug 2008 18:27:35 +0200
> >
> > > > Those banks really want to crank down on latency - to the point they
> > > > start disabling interrupt coalescing.  I bet they'd toss anything out
> > > > they could to shave another microsecond.
> > >
> > > This change would actually likely lower their latency.
> >
> > They want the timestamps, but they want it to match when the packet
> > arrived at their system as closely as is reasonably possible.
>
> Then they should use hardware time stamps which are increasingly
> available (e.g. current Intel e1000 design has them and I expect
> others too).

Would it make sense to make a new option for these socket timestamps
and encourage some apps move over to it?
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