From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: HTB accuracy for high speed Date: Mon, 18 May 2009 15:02:34 -0700 Message-ID: <20090518150234.0f57b263@nehalam> References: <298f5c050905150745p13dc226eia1ff50ffa8c4b300@mail.gmail.com> <298f5c050905150749s3597328dr8dd15adbd7a37532@mail.gmail.com> <20090515111227.7fc758cd@nehalam> <298f5c050905180301s1c4ffdb2p61a155668eb39bd2@mail.gmail.com> <20090518091314.06bf60d2@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Antonio Almeida , netdev@vger.kernel.org, jarkao2@gmail.com, kaber@trash.net, davem@davemloft.net, devik@cdi.cz To: Stephen Hemminger Return-path: Received: from mail.vyatta.com ([76.74.103.46]:49187 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751722AbZERWCj (ORCPT ); Mon, 18 May 2009 18:02:39 -0400 In-Reply-To: <20090518091314.06bf60d2@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 18 May 2009 09:13:14 -0700 Stephen Hemminger wrote: > On Mon, 18 May 2009 11:01:21 +0100 > Antonio Almeida wrote: > > > Hi! > > > > cat /sys/devices/system/clocksource/clocksource0/current_clocksource > > returns "jiffies" > > That is the slowest of the choices. Better ones are hpet and tsc, but you > hardware doesn't support them. > > You should compile your kernel with HZ=1000 and the resolution will be better > (but with some loss of performance). > -- Are you using one of the AMD dual core machines? That processor has the bad design flaw that the TSC counter is not synced between core's so the kernel can't use it. You might even be better off running a non SMP kernel on that box.