Date: Thu, 28 Aug 2008 12:36:45 -0700 (PDT)
Message-Id: <20080828.123645.78561286.davem@davemloft.net>
To: denys@visp.net.lb
Cc: andi@firstfloor.org, jmalicki@metacarta.com, johnpol@2ka.mipt.ru,
       dada1@cosmosbay.com, netdev@vger.kernel.org,
       linux-kernel@vger.kernel.org, juhlenko@akamai.com, sammy@sammy.net
Subject: Re: loaded router, excessive getnstimeofday in oprofile
From: David Miller <davem@davemloft.net>
In-Reply-To: <200808281948.52608.denys@visp.net.lb>
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From: Denys Fedoryshchenko <denys@visp.net.lb>
Date: Thu, 28 Aug 2008 19:48:52 +0300

> So there is few good solutions available (IMHO):
> 1)Introduce some SO_REALTIMESTAMP (anyway even SO_TIMESTAMP not defined in any 
> standard) for banks and ntp folks, who need them. And even give them timespec 
> instead timeval, so they will be even more happy with resolution.
> 2)Provide sysctl,kernel boot, or even "build time" option for "banks" to have 
> high resolution(and expensive) SO_TIMESTAMP.

The performance hit hurts, but changing the default to lower
resolution after it having been high resolution for 10+ years
is a regression and something we really can't do.
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