Idling ARMs in a busy world: Linux Power Management for ARM multi-cluster Systems

The advent of big.LITTLE ARM systems set the stage for the implementation of
multi-cluster of processors in nowadays SoCs. This novelty poses further
challenges at every level of system design from both HW and SW perspectives.
Performance will soon give way to power efficiency as the parameter guiding HW
and SW design decisions, especially in SoCs aimed at mobile technologies.

This talk will highlight the concepts and implementation details underlying
the ARM Linux kernel Power Management subsystems, with a detailed overview of
how suspend to RAM, CPU idle and CPU hotplug frameworks are designed for
current system on chips and how they are going to evolve to cater for the
introduction of multi-cluster systems.

Lorenzo Pieralisi, ARM Ltd., Cambridge

Lorenzo Pieralisi has worked at ARM Ltd since March 2010 as a Linux kernel
developer. He obtained a Laurea degree (summa cum laude) in Microelectronics
from the University of Ancona in March 2002. He carried out a PhD in
Microelectronics at INP Grenoble where he defended his thesis in 2005 on
on-chip interconnections for Advanced Computing. Prior to joining ARM, he
worked at the AST (Advanced System Technology) Lab of STMicroelectronics in
Grenoble France, where he spent 7 years programming kernel device drivers for
ARM processors for a variety of purposes like power management, advanced
computing and interconnect device drivers. He presented talks at DATE Europe
in 2003, ICCD 2005, SoC conference in 2008, ELC Europe 2011 and other workshops
around Europe. He is a keen and enthusiastic embedded systems programmer since
the early days of microcontrollers and got involved with Linux kernel
programming in 2006 for both personal interest and work.
He is an active open source contributor.

Amit Kucheria, working for Linaro as Canonical assignee

Amit is a long-time Linux user and has worked on network QoS, wireless routing, power management in Linux at university, a California startup and finally Nokia where he led the power management team for a while.
Lately, he's been working with the Linaro members to make Linux power management infrastructure more suitable for ARM SoCs. As Tech Lead of the Power Mangement Working Group, he gets to work with a diverse team in trying to standardize interfaces and tools for ARM power management.

Daniel Lezcano, working Linaro as IBM LTC assignee

Daniel worked in 1998 in the Space Industry and Air traffic management for distributed system project in life safety constraints. He acquired for this project a system programing expertise. He joined IBM in 2004 and since this date he does kernel hacking and pushed upstream the resource virtualization with the namespaces. In 2011, he joined the Linaro's Power Management Team and works on the kernel area, consolidating the cpuidle drivers across the different ARM SoC.