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Date:      Wed, 11 Jul 2012 09:44:44 -0500
From:      Paul Albrecht <albrecht@glccom.com>
To:        Alexander Motin <mav@FreeBSD.org>
Cc:        "davide@FreeBSD.org" <davide@FreeBSD.org>, "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>, Harti Brandt <hartmut.brandt@dlr.de>
Subject:   Re: [[SPAM]] Re: kqueue timer timeout period
Message-ID:  <1342017884.5984.24.camel@albrecht-desktop>
In-Reply-To: <4FFD4A7F.9060103@FreeBSD.org>
References:  <4FFD4A7F.9060103@FreeBSD.org>

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On Wed, 2012-07-11 at 04:42 -0500, Alexander Motin wrote:
> Hi.
> 
> Historically FreeBSD used completely different hardware time sources for 
> time keeping and time events. Not sure about 5%, but the last could be 
> less precise in some cases. FreeBSD 9.0, depending on hardware, can be 
> more precise because of using same time source in both cases. Also there 
> is ongoing GSoC project now by Davide Italiano to handle sub-HZ 
> resolution for time events. Present tests show reaching 20 microseconds 
> precision; and I think it can be improved further.
> 

I'm definitely not getting getting 20 millisecond timing with freebsd
kqueue which surprised me because I get it with linux
linuxfd_create/read using the same hardware.

-- 
Paul Albrecht




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