From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751110AbVIFXFM (ORCPT ); Tue, 6 Sep 2005 19:05:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751118AbVIFXFM (ORCPT ); Tue, 6 Sep 2005 19:05:12 -0400 Received: from fmr23.intel.com ([143.183.121.15]:42632 "EHLO scsfmr003.sc.intel.com") by vger.kernel.org with ESMTP id S1751110AbVIFXFK (ORCPT ); Tue, 6 Sep 2005 19:05:10 -0400 Date: Tue, 6 Sep 2005 16:04:29 -0700 From: Ashok Raj To: Andi Kleen Cc: akpm@osdl.org, ashok.raj@intel.com, linux-kernel@vger.kernel.org Subject: Re: [patch 14/14] x86_64: Choose physflat for AMD systems only when >8 CPUS. Message-ID: <20050906160429.A19592@unix-os.sc.intel.com> References: <200509032135.j83LZ90U020559@shell0.pdx.osdl.net> <20050905231808.GB16476@muc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20050905231808.GB16476@muc.de>; from ak@muc.de on Tue, Sep 06, 2005 at 01:18:08AM +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 06, 2005 at 01:18:08AM +0200, Andi Kleen wrote: > On Sat, Sep 03, 2005 at 02:33:30PM -0700, akpm@osdl.org wrote: > > > > From: Ashok Raj > > > > It is not required to choose the physflat mode when CPU hotplug is enabled and > > CPUs <=8 case. Use of genapic_flat with the mask version is capable of doing > > the same, instead of doing the send_IPI_mask_sequence() where its a unicast. > > I don't get the reasoning of this change. So probably not. Hummm...Please see below. Nothing has changed since then, any idea why its not acceptable now? http://marc.theaimsgroup.com/?l=linux-kernel&m=112315304423377&w=2 This really doesnt affect me, it just bothers me to go over inefficient code. send_IPI_mask_sequence() does unicast IPI's. When number of CPUs is <=8 the mask version acheives the same with just one write, so its a selective broadcast which is more efficient. Based on our earlier exchange i assumed it was clear and apparent which is why you "OK"ed the version when it was submitted to -mm. Nothing has changed, its the exact same patch. Hope its clear now. Entirely up to you... :-( -- Cheers, Ashok Raj - Open Source Technology Center