From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH v6] net: batch skb dequeueing from softnet input_pkt_queue Date: Mon, 3 May 2010 12:34:26 +0200 Message-ID: <20100503103426.GA25809@one.firstfloor.org> References: <1272783366.2173.13.camel@edumazet-laptop> <20100502092020.GA9655@gargoyle.fritz.box> <1272797690.2173.26.camel@edumazet-laptop> <20100502071324.1a95fdad@infradead.org> <1272810448.2173.31.camel@edumazet-laptop> <20100502105418.7abf83a7@infradead.org> <1272828143.2173.150.camel@edumazet-laptop> <20100502205044.450beda2@infradead.org> <1272863834.2173.173.camel@edumazet-laptop> <20100503032227.268613ac@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric Dumazet , Andi Kleen , David Miller , hadi@cyberus.ca, xiaosuo@gmail.com, therbert@google.com, shemminger@vyatta.com, netdev@vger.kernel.org, lenb@kernel.org To: Arjan van de Ven Return-path: Received: from one.firstfloor.org ([213.235.205.2]:58998 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754516Ab0ECKeb (ORCPT ); Mon, 3 May 2010 06:34:31 -0400 Content-Disposition: inline In-Reply-To: <20100503032227.268613ac@infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: > > Maybe its low cost, (apparently, it is, since I can reach ~900.000 > > ipis on my 16 cores machine) but multiply this by 16 or 32 or 64 > > cpus, and clockevents_notify() cost appears to be a killer, all cpus > > compete on a single lock. > > > > Maybe this notifier could use RCU ? > > could this be an artifact of the local apic stopping in deeper C states? > (which is finally fixed in the Westmere generation) Yes it is I think. But I suspect Eric wants a solution for Nehalem. -Andi -- ak@linux.intel.com -- Speaking for myself only.