diff mbox

[v8,3/6] arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops

Message ID 1389206998-27875-3-git-send-email-stefano.stabellini@eu.citrix.com
State New
Headers show

Commit Message

Stefano Stabellini Jan. 8, 2014, 6:49 p.m. UTC 
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>
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 v7:
- ifdef CONFIG_PARAVIRT the content of paravirt.h.

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/kernel/Makefile |    1 +
 2 files changed, 21 insertions(+)

Comments

Ian Campbell Jan. 9, 2014, 12:13 p.m. UTC | #1 
On Wed, 2014-01-08 at 18:49 +0000, Stefano Stabellini wrote:
> 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>

> 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 v7:
> - ifdef CONFIG_PARAVIRT the content of paravirt.h.
> 
> 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/kernel/Makefile |    1 +
>  2 files changed, 21 insertions(+)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index c1f1a7e..d6c3ba1 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1874,6 +1874,25 @@ 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
> @@ -1885,6 +1904,7 @@ config XEN
>  	depends on !GENERIC_ATOMIC64
>  	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/kernel/Makefile b/arch/arm/kernel/Makefile
> index a30fc9b..bcd2b38 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -87,6 +87,7 @@ 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


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diff mbox

Patch

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c1f1a7e..d6c3ba1 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1874,6 +1874,25 @@  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
@@ -1885,6 +1904,7 @@  config XEN
 	depends on !GENERIC_ATOMIC64
 	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/kernel/Makefile b/arch/arm/kernel/Makefile
index a30fc9b..bcd2b38 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -87,6 +87,7 @@  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