Re: [RFC] Add Arm cpu topology definition

2011-06-22 Thread Catalin Marinas
On Tue, Jun 21, 2011 at 01:36:15PM -0700, Stephen Boyd wrote: On 06/16/2011 11:54 PM, Vincent Guittot wrote: On 16 June 2011 21:40, Stephen Boyd sb...@codeaurora.org wrote: The ARM ARM says these fields are IMPLEMENTATION DEFINED meaning that different vendors may attribute different

Re: [RFC] Add Arm cpu topology definition

2011-06-22 Thread Amit Kucheria
On 11 Jun 22, Catalin Marinas wrote: On Tue, Jun 21, 2011 at 01:36:15PM -0700, Stephen Boyd wrote: On 06/16/2011 11:54 PM, Vincent Guittot wrote: On 16 June 2011 21:40, Stephen Boyd sb...@codeaurora.org wrote: The ARM ARM says these fields are IMPLEMENTATION DEFINED meaning that

Re: [RFC] Add Arm cpu topology definition

2011-06-21 Thread Stephen Boyd
On 06/16/2011 11:54 PM, Vincent Guittot wrote: On 16 June 2011 21:40, Stephen Boyd sb...@codeaurora.org wrote: The ARM ARM says these fields are IMPLEMENTATION DEFINED meaning that different vendors may attribute different meaning to these fields if they wish. Does that mean this should be a

Re: [RFC] Add Arm cpu topology definition

2011-06-17 Thread Vincent Guittot
On 16 June 2011 21:40, Stephen Boyd sb...@codeaurora.org wrote: On 06/16/2011 01:49 AM, Vincent Guittot wrote: +config SCHED_MC +     bool Multi-core scheduler support +     depends on SMP ARM_CPU_TOPOLOGY +     default n +     help +       Multi-core scheduler support improves the CPU

Re: [RFC] Add Arm cpu topology definition

2011-06-17 Thread Vincent Guittot
On 16 June 2011 23:13, Russell King - ARM Linux li...@arm.linux.org.uk wrote: On Thu, Jun 16, 2011 at 10:49:13AM +0200, Vincent Guittot wrote: @@ -219,6 +219,24 @@ source kernel/Kconfig.freezer  menu System Type +config SCHED_MC +     bool Multi-core scheduler support +     depends on SMP

Re: [RFC] Add Arm cpu topology definition

2011-06-17 Thread Stephen Boyd
On 06/16/2011 01:49 AM, Vincent Guittot wrote: +config SCHED_MC + bool Multi-core scheduler support + depends on SMP ARM_CPU_TOPOLOGY + default n + help + Multi-core scheduler support improves the CPU scheduler's decision + making when dealing with multi-core

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Daniel Lezcano
On 06/16/2011 10:49 AM, Vincent Guittot wrote: The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance interdependency. The cpu topology of an Arm platform can be set thanks to this register

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Amit Kucheria
On 11 Jun 16, Vincent Guittot wrote: The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance interdependency. The cpu topology of an Arm platform can be set thanks to this register and this

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Amit Kachhap
I have some doubts about the bit fields of the MPIDR register. Comments added below. On 16 June 2011 14:19, Vincent Guittot vincent.guit...@linaro.org wrote: The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Vincent Guittot
On 16 June 2011 12:49, Daniel Lezcano daniel.lezc...@linaro.org wrote: On 06/16/2011 10:49 AM, Vincent Guittot wrote: The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Vincent Guittot
On 16 June 2011 13:48, Amit Kucheria amit.kuche...@linaro.org wrote: On 11 Jun 16, Vincent Guittot wrote: The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance interdependency. The cpu

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Christian Robottom Reis
On Thu, Jun 16, 2011 at 10:49:13AM +0200, Vincent Guittot wrote: @@ -219,6 +219,24 @@ source kernel/Kconfig.freezer menu System Type +config SCHED_MC + bool Multi-core scheduler support + depends on SMP ARM_CPU_TOPOLOGY + default n + help + Multi-core scheduler

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Samuel Thibault
Vincent Guittot, le Thu 16 Jun 2011 11:44:30 +0200, a écrit : The output of hwloc-gather-topology is : Machine (phys=0 local=280840KB total=280840KB) Socket #0 (phys=3) Core #0 (phys=0) PU #0 (phys=0) Core #1 (phys=1) PU #1 (phys=1) depth 0:1 Machine (type

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Samuel Thibault
Hello, Vincent Guittot, le Thu 16 Jun 2011 10:49:13 +0200, a écrit : The affinity between Arm processors is defined in the MPIDR register. We can identify which processors are in the same cluster, and which ones have performance interdependency. The cpu topology of an Arm platform can be set

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Vincent Guittot
On 16 June 2011 15:24, Christian Robottom Reis k...@linaro.org wrote: On Thu, Jun 16, 2011 at 10:49:13AM +0200, Vincent Guittot wrote: @@ -219,6 +219,24 @@ source kernel/Kconfig.freezer  menu System Type +config SCHED_MC +     bool Multi-core scheduler support +     depends on SMP

Re: [RFC] Add Arm cpu topology definition

2011-06-16 Thread Russell King - ARM Linux
On Thu, Jun 16, 2011 at 10:49:13AM +0200, Vincent Guittot wrote: @@ -219,6 +219,24 @@ source kernel/Kconfig.freezer menu System Type +config SCHED_MC + bool Multi-core scheduler support + depends on SMP ARM_CPU_TOPOLOGY + default n + help + Multi-core scheduler