From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: Re: [PATCH 2/2] x86: get more exact nr_irqs Date: Mon, 04 Jan 2010 11:47:07 -0800 Message-ID: <4B4245BB.5070302@kernel.org> References: <4B347AEE.6030705@kernel.org> <20091228094707.GH24690@elte.hu> <4B398ECD.1080506@kernel.org> <4807377b1001031906s6b1ee576jc021da2642bb4147@mail.gmail.com> <4B415E73.1050801@kernel.org> <4B41918D.3000605@kernel.org> <86802c441001041103s5abd6d3ai4e6ccbfc68323f3c@mail.gmail.com> <4B4241E2.1020008@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: "Eric W. Biederman" , Jesse Brandeburg , Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" , Andrew Morton , NetDEV list , Jesse Brandeburg To: "H. Peter Anvin" Return-path: Received: from hera.kernel.org ([140.211.167.34]:51506 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751086Ab0ADTsq (ORCPT ); Mon, 4 Jan 2010 14:48:46 -0500 In-Reply-To: <4B4241E2.1020008@zytor.com> Sender: netdev-owner@vger.kernel.org List-ID: On 01/04/2010 11:30 AM, H. Peter Anvin wrote: > On 01/04/2010 11:16 AM, Eric W. Biederman wrote: >> >> If we care about memory use efficiency let's replace irq_desc_ptrs >> with a rbtree or a radix_tree. Something that moves the memory use >> penalty onto those machines that have a lot of irqs. >> > > rbtree doesn't make much sense for something that is addressed by index, > and doesn't need to answer questions of the form "give me the highest > member <= X". A hash table or radix tree makes sense, depending on the > expected sparseness of the index. will check if we can use radix with it like powerpc YH