From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755948AbXKMK7Z (ORCPT ); Tue, 13 Nov 2007 05:59:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753309AbXKMK7R (ORCPT ); Tue, 13 Nov 2007 05:59:17 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:56285 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752935AbXKMK7Q (ORCPT ); Tue, 13 Nov 2007 05:59:16 -0500 Subject: Re: [PATCH, RFC] improved hacks to allow -rt to run kernbench on POWER From: Peter Zijlstra To: benh@kernel.crashing.org Cc: paulmck@linux.vnet.ibm.com, Steven Rostedt , linux-kernel@vger.kernel.org, tony@bakeyournoodle.com, paulus@samba.org, dino@in.ibm.com, tytso@us.ibm.com, dvhltc@us.ibm.com, niv@us.ibm.com, antonb@us.ibm.com, Ingo Molnar In-Reply-To: <1194948338.6983.20.camel@twins> References: <20071109181028.GA26800@linux.vnet.ibm.com> <1194641524.21340.14.camel@pasglop> <20071109220717.GJ8826@linux.vnet.ibm.com> <1194753541.21340.26.camel@pasglop> <1194814125.6510.14.camel@pasglop> <20071112191526.GC11113@linux.vnet.ibm.com> <1194901925.18185.65.camel@pasglop> <1194945032.6983.11.camel@twins> <1194948338.6983.20.camel@twins> Content-Type: text/plain Date: Tue, 13 Nov 2007 11:59:05 +0100 Message-Id: <1194951545.6983.26.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2007-11-13 at 11:05 +0100, Peter Zijlstra wrote: > Anyway, it seems its the generic irq stuff that uses raw_spinlock_t and > disables IRQs, so there isn't much we can do from the ARCH level I'm > afraid :-( > > Ingo, any sane ideas? Ok benh came up with a workable idea, he just needs a night's sleep to come up with the details :-) The idea is to fill the radix tree from host->ops->map() (or irq_create_mapping()) as that should still be preemptable, and then convert all other uses to RCU lookups.