From patchwork Wed May 8 15:41:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 2539911 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork2.kernel.org (Postfix) with ESMTP id EF00EDF2E5 for ; Wed, 8 May 2013 15:46:06 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ua6XU-0000al-33; Wed, 08 May 2013 15:44:20 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ua6W7-0004E9-Gx; Wed, 08 May 2013 15:42:55 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ua6W3-0004BB-Gc for linux-arm-kernel@lists.infradead.org; Wed, 08 May 2013 15:42:53 +0000 X-IronPort-AV: E=Sophos;i="4.87,635,1363132800"; d="scan'208";a="24043605" Received: from accessns.citrite.net (HELO FTLPEX01CL03.citrite.net) ([10.9.154.239]) by FTLPIPO01.CITRIX.COM with ESMTP/TLS/AES128-SHA; 08 May 2013 15:42:03 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.80) with Microsoft SMTP Server id 14.2.342.3; Wed, 8 May 2013 11:42:02 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1Ua6VA-0007fa-QW; Wed, 08 May 2013 16:41:56 +0100 From: Stefano Stabellini To: Subject: [PATCH v3 3/4] arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops Date: Wed, 8 May 2013 16:41:53 +0100 Message-ID: <1368027714-14506-3-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130508_114251_775451_B53DB874 X-CRM114-Status: GOOD ( 15.64 ) X-Spam-Score: -8.3 (--------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-8.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [66.165.176.89 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record -1.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: linux@arm.linux.org.uk, arnd@arndb.de, Stefano Stabellini , marc.zyngier@arm.com, konrad.wilk@oracle.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, nico@linaro.org, olof@lixom.net, linux-arm-kernel@lists.infradead.org, cov@codeaurora.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM. The only paravirt interface supported is pv_time_ops.steal_clock, so no runtime pvops patching needed. This allows us to make use of steal_account_process_tick for stolen ticks accounting. Changes in v3: - improve commit description and Kconfig help text; - no need to initialize pv_time_ops; - add PARAVIRT_TIME_ACCOUNTING. Signed-off-by: Stefano Stabellini CC: linux@arm.linux.org.uk CC: will.deacon@arm.com CC: nico@linaro.org CC: marc.zyngier@arm.com CC: cov@codeaurora.org CC: arnd@arndb.de CC: olof@lixom.net --- arch/arm/Kconfig | 20 ++++++++++++++++++++ arch/arm/include/asm/paravirt.h | 19 +++++++++++++++++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/paravirt.c | 25 +++++++++++++++++++++++++ 4 files changed, 65 insertions(+), 0 deletions(-) create mode 100644 arch/arm/include/asm/paravirt.h create mode 100644 arch/arm/kernel/paravirt.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 344e299..89ee2f1 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1887,12 +1887,32 @@ config XEN_DOM0 def_bool y depends on XEN +config PARAVIRT + bool "Enable paravirtualization code" + ---help--- + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. + +config PARAVIRT_TIME_ACCOUNTING + bool "Paravirtual steal time accounting" + select PARAVIRT + default n + ---help--- + Select this option to enable fine granularity task steal time + accounting. Time spent executing other tasks in parallel with + the current vCPU is discounted from the vCPU power. To account for + that, there can be a small performance impact. + + If in doubt, say N here. + config XEN bool "Xen guest support on ARM (EXPERIMENTAL)" depends on ARM && AEABI && OF depends on CPU_V7 && !CPU_V6 depends on !GENERIC_ATOMIC64 select ARM_PSCI + select PARAVIRT help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. diff --git a/arch/arm/include/asm/paravirt.h b/arch/arm/include/asm/paravirt.h new file mode 100644 index 0000000..3b95bc6 --- /dev/null +++ b/arch/arm/include/asm/paravirt.h @@ -0,0 +1,19 @@ +#ifndef _ASM_ARM_PARAVIRT_H +#define _ASM_ARM_PARAVIRT_H + +struct static_key; +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops { + unsigned long long (*steal_clock)(int cpu); +}; +extern struct pv_time_ops pv_time_ops; + +static inline u64 paravirt_steal_clock(int cpu) +{ + return pv_time_ops.steal_clock(cpu); +} + + +#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5f3338e..d911db6 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_ARM_CPU_TOPOLOGY) += topology.o ifneq ($(CONFIG_ARCH_EBSA110),y) obj-y += io.o endif +obj-$(CONFIG_PARAVIRT) += paravirt.o head-y := head$(MMUEXT).o obj-$(CONFIG_DEBUG_LL) += debug.o diff --git a/arch/arm/kernel/paravirt.c b/arch/arm/kernel/paravirt.c new file mode 100644 index 0000000..53f371e --- /dev/null +++ b/arch/arm/kernel/paravirt.c @@ -0,0 +1,25 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2013 Citrix Systems + * + * Author: Stefano Stabellini + */ + +#include +#include +#include +#include + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops pv_time_ops; +EXPORT_SYMBOL_GPL(pv_time_ops);