Overview

All CES computing elements, independent of their form factor (VPX, VXS, VME, CompactPCI, PMC, custom), directly incorporate in their hardware building blocks, a unique ultra-high-speed inter-processor extension, which delivers a client-server type network protocol overlaying the physical layers (VME, CompactPCI, PCI, high-speed serial links), delivering network services at the full hardware speed.

BP-Net is available under all of the CES supported operating systems, which allows to mix operating systems on the same platform (in the case of multiple processor platforms), while guaranteeing seamless high-speed data transfers.

High-Speed Multiprocessor Extension

The complexity of today’s research programs often leads to multiprocessor-based applications. An efficient inter-processor communication and synchronization, combining microsecond-level resolution, the capability to distribute tasks between all processors present in the system and network-oriented services, are the keys to success. CES BP-Net is an inter-process communication system. It allows a process to easily send data (messages) to another process without worrying about handling the physical transmission media. It offers three types of services to ensure efficient communication between CES processors:

• Inter-process communication: This mechanism allows the processes of any processor to share resources and preserve the integrity of these resources. It covers the functionalities of remote DMA channels, semaphores and message queues.
• Efficient and straight-forward message passing system (the channel library): This functionality is very close to the hardware and fully exploits its potential to optimize the performance (high-speed DMAs).
• Full TCP/IP stack using the VME, CompactPCI or PCI bus or high-speed serial links as a network device: This permits an easy development of TCP/IP-based applications, which can be distributed over clusters of CES processor boards. In addition, this gives access to the set of tools associated with TCP/IP (NFS, remote login, etc.) at a very high-speed.

Channel-Based Communication

CES BP-Net is a software package including a library and a driver installed on every processor, which may execute processes involving a channel-based communication. The driver takes control of all of the difficulties associated with the use of the bus (programming of DMAs, interrupt management, alignment, errors, mapping, etc.). All of the physical resources of the boards are used in order to optimize the performance of the transfer of the data (DMA-specific, FIFOs). The programmer needs only to consider the logical point-of-view of communicating through channels and never needs to take into account the characteristics of the used material. CES BP-Net is available under all of the operating systems supported by CES processor boards.

Media Independent

CES BP-Net has been designed to be independent from the transmission media used for the connection:

• PCI between MFCCs and a RIOx motherboard
• VME, CompactPCI or high-speed serial links for inter-chassis or workstation-to-chassis connections

One process can establish a connection either by specifying explicitly the processor on which the other process is being executed, or by using a “label”. In this case, a “Channel Name Server” automatically allows the two processes to connect together without requiring the knowledge of their respective locations. Using labels permits the launching of successive executions of a multi-process application, while allowing to relocate the processes to different processors, from one execution to the other, without recompiling the application.

CES BP-Net