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 17:52:04 +0200 Message-ID: <20100503155204.GA6200@gargoyle.fritz.box> References: <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> <20100503103426.GA25809@one.firstfloor.org> <20100503070925.572bbee6@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric Dumazet , 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]:43164 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753075Ab0ECPtd (ORCPT ); Mon, 3 May 2010 11:49:33 -0400 Content-Disposition: inline In-Reply-To: <20100503070925.572bbee6@infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: > so the hard problem is that on going idle, the local timers need to be > funneled to the external HPET. Afaik right now we use one channel of > the hpet, with the result that we have one global lock for this. > > HPETs have more than one channel (2 or 3 historically, newer chipsets > iirc have a few more), so in principle we can split this lock at least > a little bit... if we can get to one hpet channel per level 3 cache > domain we'd already make huge progress in terms of cost of the > contention.... I suggested the same thing a few emails up @) (great minds think alike etc.etc. @) . I'm not sure how difficult it would be to implement though. Potential issues: Some user applications use the hpet channels directly through the character device interface so there would be a potential compatibility issue (but maybe that should be just moved to be emulated with a hrtimer ?) And if multiple broadcast controllers are elected this might make it harder to become idle. -Andi