netdev - Re: Using jiffies for tcp_time

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Message-ID: <1337972432.3347.70.camel@edumazet-glaptop>
Date:	Fri, 25 May 2012 21:00:32 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Srećko Jurić-Kavelj 
	<srecko.juric-kavelj@....hr>
Cc:	Dave Taht <dave.taht@...il.com>,
	Chris Friesen <chris.friesen@...band.com>,
	netdev@...r.kernel.org
Subject: Re: Using jiffies for tcp_time_stamp?

On Fri, 2012-05-25 at 20:35 +0200, Srećko Jurić-Kavelj wrote:

> From what I've seen in the code, NO_HZ doesn't make jiffies go away,
> it simply doesn't use regular CONFIG_HZ interrupt to update, but
> updates them when has an opportunity?

HZ=1000 makes jiffies 10 times more precise, and with NO_HZ, generates
no extra timer interrupts.

This also makes timers workload smoothed, instead of spikes.



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