Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933009Ab2JKQrE (ORCPT ); Thu, 11 Oct 2012 12:47:04 -0400 Received: from g1t0026.austin.hp.com ([15.216.28.33]:16501 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932122Ab2JKQq7 (ORCPT ); Thu, 11 Oct 2012 12:46:59 -0400 From: "Zhang, Lin-Bao (Linux Kernel R&D)" To: Suresh Siddha CC: "linux-kernel@vger.kernel.org" , "alan@lxorguk.ukuu.org.uk" , "mingo@redhat.com" , "Croxon, Nigel" , "tglx@linutronix.de" , "hpa@zytor.com" , "x86@kernel.org" , "a.p.zijlstra@chello.nl" , "Sakkinen, Jarkko" , "joerg.roedel@amd.com" , "agordeev@redhat.com" , "yinghai@kernel.org" , "Zhang, Lin-Bao (Linux Kernel R&D)" Subject: RE: [PATCH] fix x2apic defect that Linux kernel doesn't mask 8259A interrupt during the time window between changing VT-d table base address and initializing these VT-d entries(smpboot.c and apic.c ) Thread-Topic: [PATCH] fix x2apic defect that Linux kernel doesn't mask 8259A interrupt during the time window between changing VT-d table base address and initializing these VT-d entries(smpboot.c and apic.c ) Thread-Index: AQHNpbB+Rz0tU9hpbEaEjcKbxJEEKZexnhfwgAF40ICAACTkgIABFSNA Date: Thu, 11 Oct 2012 16:46:29 +0000 Message-ID: <92645B27BF79D04FBD2B0F8494FFD0F9102B85@G2W2429.americas.hpqcorp.net> References: <92645B27BF79D04FBD2B0F8494FFD0F90FC806@G2W2429.americas.hpqcorp.net> <1349740633.11093.43.camel@sbsiddha-desk.sc.intel.com> <92645B27BF79D04FBD2B0F8494FFD0F9102841@G2W2429.americas.hpqcorp.net> <1349913700.3042.7.camel@sbsiddha-desk.sc.intel.com> In-Reply-To: <1349913700.3042.7.camel@sbsiddha-desk.sc.intel.com> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [16.193.232.10] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id q9BGl7cO012042 Content-Length: 1032 Lines: 26 > -----Original Message----- > From: Suresh Siddha [mailto:suresh.b.siddha@intel.com] > Sent: 2012年10月10日 18:02 > > > So I looked at why you are seeing the problem with v2.6.32 but not > > > with the recent kernels. And I think I found out the reason. > > > > I want to know what masking IO-APIC means? > > As the platform is configured to use virtual-wire B and the corresponding > IO-APIC RTE is masked, that interrupt will be dropped. > thanks for your explanation and confirm, I also consulted BIOS guys , yes, interrupt will be dropped , software didn't see them,and don't go to handle them. So we OS don't need to disable 8259A interrupt during the window , only if 2.6.32 has applied your patch(triggered some actions to mask IO-apic) That's good. Perfect design . thanks. Here we go! --------------- -- Bob(LinBao Zhang) HP linux kernel enginner ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?