From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753356AbYJCPFp (ORCPT ); Fri, 3 Oct 2008 11:05:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752235AbYJCPFh (ORCPT ); Fri, 3 Oct 2008 11:05:37 -0400 Received: from mga12.intel.com ([143.182.124.36]:61140 "EHLO azsmga102.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752075AbYJCPFg (ORCPT ); Fri, 3 Oct 2008 11:05:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.33,356,1220252400"; d="scan'208";a="54646543" Message-ID: <48E634B7.60002@linux.intel.com> Date: Fri, 03 Oct 2008 08:05:27 -0700 From: Arjan van de Ven User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Jason Baron CC: Jan Kasprzak , linux-kernel@vger.kernel.org Subject: Re: IRQ balancing on a router References: <20081003132117.GM16624@fi.muni.cz> <20081003063857.76b7b61a@linux.intel.com> <20081003142941.GC3167@redhat.com> In-Reply-To: <20081003142941.GC3167@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jason Baron wrote: >> one of the hard cases for irqbalance is that irqbalance doesn't have a >> way to find out the actual cpu time spend in the handlers. For >> networking it makes an estimate just based on the number of packets >> (which is better than nothing)... but that breaks down if you have an >> non-symmetry in CPU costs per packet like you have. >> >> The good news is that irqthreads at least have the potential to solve >> this "lack of information"; if not, we could consider doing a form of >> microaccounting for irq handlers.... >> >> > > perhaps, this could be addressed using tracepoints. The currently > proposed ones are at the beginning and end of 'handle_IRQ_event()'. See: > http://marc.info/?l=linux-kernel&m=121616099830280&w=2 > something that you always need should not be a tracepoint.