diff options
author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2015-11-23 13:32:57 +0300 |
---|---|---|
committer | David Vrabel <david.vrabel@citrix.com> | 2015-12-21 17:40:54 +0300 |
commit | 02c2433b3aa6b57313c261c9811bbbe49528101c (patch) | |
tree | 8081453d55ffc7b54560cd99e069a9890ee7ea68 /arch | |
parent | 1fe7c4ef88bd32e039f5f4126537c3f20c340414 (diff) | |
download | linux-02c2433b3aa6b57313c261c9811bbbe49528101c.tar.xz |
arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops
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 <stefano.stabellini@eu.citrix.com>
Acked-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Russell King <linux@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm/Kconfig | 20 | ||||
-rw-r--r-- | arch/arm/include/asm/paravirt.h | 20 | ||||
-rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/kernel/paravirt.c | 25 |
4 files changed, 66 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 34e1569a11ee..1ab9b98d4c6c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1800,6 +1800,25 @@ config SWIOTLB config IOMMU_HELPER def_bool SWIOTLB +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_DOM0 def_bool y depends on XEN @@ -1813,6 +1832,7 @@ config XEN select ARCH_DMA_ADDR_T_64BIT select ARM_PSCI select SWIOTLB_XEN + 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 000000000000..8435ff591386 --- /dev/null +++ b/arch/arm/include/asm/paravirt.h @@ -0,0 +1,20 @@ +#ifndef _ASM_ARM_PARAVIRT_H +#define _ASM_ARM_PARAVIRT_H + +#ifdef CONFIG_PARAVIRT +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 + +#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index af9e59bf3831..3e6e93725ca7 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_VDSO) += vdso.o ifneq ($(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 000000000000..53f371ed4568 --- /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 <stefano.stabellini@eu.citrix.com> + */ + +#include <linux/export.h> +#include <linux/jump_label.h> +#include <linux/types.h> +#include <asm/paravirt.h> + +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); |