Linux Plumbers Conf 2009

Excerpt

Description

CPUs are now cheap, so it is not surprising to see many embedded system designs containing more than one CPU. Aside from the familiar Symmetric Multiprocessing (SMP) arrangement, many systems use some form of Asymmetric Multiprocessing (AMP) which divides responsibilities between CPUs and runs independent operating system instances on each core. There are many reasons why a system designer may choose and AMP design, but doing so means that none of the available Linux IPC mechanisms are usable between processors.

While there are many methods of IPC between CPUs available (serial links, fifos, etc), this session focuses specifically on using shared memory regions for IPC, whether it be CPUs connected via a PCI bus, dual port RAM, or multiple processors sharing the same physical address space (ie. an SMP chip used for AMP). Linux is used in such systems, but mainline kernel doesn’t currently contain any infrastructure for supporting shared memory IPC between independent operating system instances.

This session is to discuss and debate shared memory IPC in AMP systems. We will discuss the services desired (virtual serial, virtual network, sockets, remote procedure call, etc), the implementation options (virtio pver PCI, TI’s DSPLINK, others?), working with non-Linux OS instances, and whether or not it is even feasible to implement a common set of shared memory IPC tools to be merged into the mainline kernel. Participants can and should bring up any real world issues that they are encountering with Linux on Asymmetric Multiprocessing systems.

Tags

AMP

Speaker

• Grant Likely

  Secret Lab
  • Website: http://secretlab.ca/

  Biography

  Grant Likely has spent the last 14 years building embedded systems for the military and telecom industries. Over the course of several embedded Linux projects, Grant became an active PowerPC developer and Linux maintainer of the Xilinx Virtex and the Freescale MPC5xxx platforms. In 2005 he founded Secret Lab Technologies Ltd., an embedded Linux engineering company, where he continues to play with unique hardware and tries not to let the magic smoke out.