Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936386AbXHHSXR (ORCPT ); Wed, 8 Aug 2007 14:23:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754964AbXHHSW7 (ORCPT ); Wed, 8 Aug 2007 14:22:59 -0400 Received: from dgate1.fujitsu-siemens.com ([217.115.66.35]:65482 "EHLO dgate1.fujitsu-siemens.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751135AbXHHSW7 (ORCPT ); Wed, 8 Aug 2007 14:22:59 -0400 DomainKey-Signature: s=s768; d=fujitsu-siemens.com; c=nofws; q=dns; b=gU53NPZ18h3KzD5i2pk4Xp2BEOTKcK/5ZIsXaE+bq6sHE5ZkwPyQPO5ulZ5e7aVWK0pK/p4HzQW9JCyitJPgCqGLQSMBaIx6B7z4OpsE2sh7tqgqc4jfId6sXSiQxKIE; X-SBRSScore: None X-IronPort-AV: E=Sophos;i="4.19,236,1183327200"; d="scan'208";a="88116930" Message-ID: <46BA09FE.2070909@fujitsu-siemens.com> Date: Wed, 08 Aug 2007 20:22:54 +0200 From: Martin Wilck Organization: Fujitsu Siemens Computers User-Agent: Thunderbird 1.5.0.8 (X11/20061025) MIME-Version: 1.0 To: "Eric W. Biederman" Cc: "vgoyal@in.ibm.com" , Haren Myneni , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: PATCH/RFC: [kdump] fix APIC shutdown sequence References: <46B73955.2080007@fujitsu-siemens.com> <20070807142928.GA18839@in.ibm.com> <46B8AECA.7050908@fujitsu-siemens.com> <46B986D5.2010407@fujitsu-siemens.com> <46B9FEC8.20004@fujitsu-siemens.com> In-Reply-To: X-Enigmail-Version: 0.94.2.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1683 Lines: 48 Eric W. Biederman wrote: >> I think a lot would be gained if disable_IO_APIC() would just mask the IRQs >> (like the function in my patch does), and perhaps fix the dest ID, instead of >> totally clearing the registers. > > Even masked we still won't see the EOI, because then we are in i8259 > mode. So masked versus totally cleared really should make no > difference. You are talking about EOI sent in the kdump kernel, correct? With my patch the EOI (sent in the "old" kernel) is seen. > I guess right now I can see work put into cleaning things up a little > or not having to call disable_IO_APIC() at all. that was supposed > to be a short term hack, until we fixed things properly. > > So far no one has been brave enough to mess with the kernel apic > initialization order so we can remove disable_IO_APIC. If our > goal isn't to fix things properly by removing the need for > disable_IO_APIC I don't feel like putting much effort into this > code path. Who is working on this? Can you give a reference to a list of things that would need to be done to do this right? Martin -- Martin Wilck PRIMERGY System Software Engineer FSC IP ESP DE6 Fujitsu Siemens Computers GmbH Heinz-Nixdorf-Ring 1 33106 Paderborn Germany Tel: ++49 5251 8 15113 Fax: ++49 5251 8 20409 Email: mailto:martin.wilck@fujitsu-siemens.com Internet: http://www.fujitsu-siemens.com Company Details: http://www.fujitsu-siemens.com/imprint.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/