From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265974AbUBCLHx (ORCPT ); Tue, 3 Feb 2004 06:07:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265981AbUBCLHx (ORCPT ); Tue, 3 Feb 2004 06:07:53 -0500 Received: from mail023.syd.optusnet.com.au ([211.29.132.101]:34536 "EHLO mail023.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S265974AbUBCLHs (ORCPT ); Tue, 3 Feb 2004 06:07:48 -0500 From: Con Kolivas To: Ingo Molnar Subject: Re: [PATCH] 2.6.1 Hyperthread smart "nice" 2 Date: Tue, 3 Feb 2004 22:07:38 +1100 User-Agent: KMail/1.6 Cc: linux kernel mailing list , Nick Piggin References: <200401291917.42087.kernel@kolivas.org> <200402032152.46481.kernel@kolivas.org> <20040203105758.GA7783@elte.hu> In-Reply-To: <20040203105758.GA7783@elte.hu> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200402032207.38006.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 3 Feb 2004 21:58, Ingo Molnar wrote: > * Con Kolivas wrote: > > At least it appears Intel are well aware of the priority problem, but > > full priority support across logical cores is not likely. However I > > guess these new instructions are probably enough to work with if > > someone can do the coding. > > these instructions can be used in the idle=poll code instead of rep-nop. > This way idle-wakeup can be done via the memory bus in essence, and the > idle threads wont waste CPU time. (right now idle=poll wastes lots of > cycles on HT boxes and is thus unusable.) Thanks for explaining. > for lowprio tasks they are of little use, unless you modify gcc to > sprinkle mwait yields all around the 'lowprio code' - not very practical > i think. Yuck! Looks like the kernel is the only thing likely to be smart enough to do this correctly for some time yet. Nick, any chance of seeing something like this in your sched domains? (that would be the right way unlike my hacking sched.c directly for a specific architecture). Con