Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964970Ab3E1Rz2 (ORCPT ); Tue, 28 May 2013 13:55:28 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:15517 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964920Ab3E1Ry5 (ORCPT ); Tue, 28 May 2013 13:54:57 -0400 X-IronPort-AV: E=Sophos;i="4.87,759,1363132800"; d="scan'208";a="26477161" From: Stefano Stabellini To: CC: , , , , , , , "Stefano Stabellini" , , , , , Subject: [PATCH v4 3/4] arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops Date: Tue, 28 May 2013 18:54:31 +0100 Message-ID: <1369763672-12919-3-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 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4369 Lines: 143 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. 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 Changes in v3: - improve commit description and Kconfig help text; - no need to initialize pv_time_ops; - add PARAVIRT_TIME_ACCOUNTING. --- 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 49d993c..5621a02 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1786,12 +1786,32 @@ 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); -- 1.7.2.5 -- 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/