From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755266Ab2DWV7L (ORCPT ); Mon, 23 Apr 2012 17:59:11 -0400 Received: from casper.infradead.org ([85.118.1.10]:33865 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753828Ab2DWV7J convert rfc822-to-8bit (ORCPT ); Mon, 23 Apr 2012 17:59:09 -0400 Message-ID: <1335218328.28150.181.camel@twins> Subject: Re: [PATCH 05/16] sched: SCHED_DEADLINE policy implementation. From: Peter Zijlstra To: Tommaso Cucinotta Cc: Juri Lelli , tglx@linutronix.de, mingo@redhat.com, rostedt@goodmis.org, cfriesen@nortel.com, oleg@redhat.com, fweisbec@gmail.com, darren@dvhart.com, johan.eker@ericsson.com, p.faure@akatech.ch, linux-kernel@vger.kernel.org, claudio@evidence.eu.com, michael@amarulasolutions.com, fchecconi@gmail.com, nicola.manica@disi.unitn.it, luca.abeni@unitn.it, dhaval.giani@gmail.com, hgu1972@gmail.com, paulmck@linux.vnet.ibm.com, raistlin@linux.it, insop.song@ericsson.com, liming.wang@windriver.com Date: Mon, 23 Apr 2012 23:58:48 +0200 In-Reply-To: <4F95CFBF.1050000@sssup.it> References: <1333696481-3433-1-git-send-email-juri.lelli@gmail.com> <1333696481-3433-6-git-send-email-juri.lelli@gmail.com> <1335182113.28150.132.camel@twins> <4F95CFBF.1050000@sssup.it> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2012-04-23 at 22:55 +0100, Tommaso Cucinotta wrote: > why not write this straight in asm, i.e., multiply 64*64 then divide by > 64 keeping the intermediate result on 128 bits? If you know of a way to do this for all 30 odd architectures supported by our beloved kernel, do let me know ;-) Yes I can do it for x86_64, but people tend to get mighty upset if you break the compile for all other arches...