From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] x86/apic: remove the legacy bigsmp APIC driver Date: Tue, 27 Aug 2013 19:10:56 +0100 Message-ID: References: <521C7CC102000078000EEA76@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VENjL-0002iy-U4 for xen-devel@lists.xenproject.org; Tue, 27 Aug 2013 18:11:04 +0000 Received: by mail-we0-f171.google.com with SMTP id p57so4254280wes.16 for ; Tue, 27 Aug 2013 11:11:02 -0700 (PDT) In-Reply-To: <521C7CC102000078000EEA76@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Matt Wilson Cc: Andrew Cooper , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 27/08/2013 09:17, "Jan Beulich" wrote: >>>> On 27.08.13 at 07:44, Matt Wilson wrote: >> The bigsmp APIC driver was used on legacy (32-bit only) x86 platforms >> with 8 or more CPUs. In Linux the X86_BIGSMP Kconfig option depends on >> X86_32. Since we no longer support 32-bit hypervisors on the x86 >> platform we can remove this code. > > The fact that this is 32-bit only in Linux doesn't mean anything. > Linux has other 64-bit only models, which we don't have (in > favor of, originally, having a single shared implementation). > > On a system without x2APIC but more than 8 CPUs - how would > you see us bringing up the CPUs beyond 8? This is particularly > shown by your adjustment to MP_processor_info_x(), which is > code removal without replacement. > > Despite Keir's ack, unless I'm overlooking something I'm explicitly > nack-ing this. Thanks. You are right of course. Oops! > Jan >