Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932979AbaJUTKQ (ORCPT ); Tue, 21 Oct 2014 15:10:16 -0400 Received: from smtp.citrix.com ([66.165.176.89]:57497 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932367AbaJUTKO (ORCPT ); Tue, 21 Oct 2014 15:10:14 -0400 X-IronPort-AV: E=Sophos;i="5.04,763,1406592000"; d="scan'208";a="183577651" Message-ID: <5446AF91.8070907@citrix.com> Date: Tue, 21 Oct 2014 20:10:09 +0100 From: Andrew Cooper User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.8.1 MIME-Version: 1.0 To: Boris Ostrovsky , , CC: , Subject: Re: [Xen-devel] [PATCH 2/2] xen/pci: Use APIC directly when APIC virtualization is supported by hardware References: <1413918075-26146-1-git-send-email-boris.ostrovsky@oracle.com> <1413918075-26146-3-git-send-email-boris.ostrovsky@oracle.com> In-Reply-To: <1413918075-26146-3-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/10/14 20:01, Boris Ostrovsky wrote: > When hardware supports APIC/x2APIC virtualization we don't need to use pirqs > for MSI handling and instead use APIC since most APIC accesses (MMIO or MSR) > will now be processed without VMEXITs. > > As an example, netperf on the original code produces this profile > (collected wih 'xentrace -e 0x0008ffff -T 5'): > > 342 cpu_change > 260 CPUID > 34638 HLT > 64067 INJ_VIRQ > 28374 INTR > 82733 INTR_WINDOW > 10 NPF > 24337 TRAP > 370610 vlapic_accept_pic_intr > 307528 VMENTRY > 307527 VMEXIT > 140998 VMMCALL > 127 wrap_buffer > > After applying this patch the same test shows > > 230 cpu_change > 260 CPUID > 36542 HLT > 174 INJ_VIRQ > 27250 INTR > 222 INTR_WINDOW > 20 NPF > 24999 TRAP > 381812 vlapic_accept_pic_intr > 166480 VMENTRY > 166479 VMEXIT > 77208 VMMCALL > 81 wrap_buffer > > ApacheBench results (ab -n 10000 -c 200) improve by about 10% > > Signed-off-by: Boris Ostrovsky > --- > arch/x86/include/asm/xen/cpuid.h | 81 ++++++++++++++++++++++++++++++++++++++++ > arch/x86/pci/xen.c | 9 +++++ > 2 files changed, 90 insertions(+) > create mode 100644 arch/x86/include/asm/xen/cpuid.h > > diff --git a/arch/x86/include/asm/xen/cpuid.h b/arch/x86/include/asm/xen/cpuid.h > new file mode 100644 > index 0000000..e57a457 > --- /dev/null > +++ b/arch/x86/include/asm/xen/cpuid.h > @@ -0,0 +1,81 @@ > +/****************************************************************************** > + * arch-x86/cpuid.h > + * > + * CPUID interface to Xen. > + * > + * Permission is hereby granted, free of charge, to any person obtaining a copy > + * of this software and associated documentation files (the "Software"), to > + * deal in the Software without restriction, including without limitation the > + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or > + * sell copies of the Software, and to permit persons to whom the Software is > + * furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice shall be included in > + * all copies or substantial portions of the Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER > + * DEALINGS IN THE SOFTWARE. > + * > + * Copyright (c) 2007 Citrix Systems, Inc. > + * > + * Authors: > + * Keir Fraser > + */ > + > +#ifndef __XEN_PUBLIC_ARCH_X86_CPUID_H__ > +#define __XEN_PUBLIC_ARCH_X86_CPUID_H__ > + > +/* Xen identification leaves start at 0x40000000. */ On reading this, I notice that the Xen header files are wrong. I will submit a correction. ~Andrew -- 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/