What Price High-Performance I/O?
If you have been around the PC industry for a while, you most likely remember that the ISA architecture (AT bus as it was initially called) was recognized as not the best answer for high performance I/O, because of speed limitations and rather poor interrupt structure. Enter IBM with its MicroChannel architecture. All you had to do was pay IBM money, and you could use the design. Some manufacturers bought in, but it soon flopped because what the industry really wanted was an open standard. In fact, AT bus became ISA (Industry Standard Architecture) because of IBM's proprietary approach.
However, ISA still wasn't the answer. The first issue, bus speed, was addressed with the PCI bus which, being wider and faster, has satisfied the bandwidth requirements of I/O hungry systems. But, as the speed of everything has increased, so has the number of interrupts that must be dealt with.
The best solution is to have intelligent peripherals that don't have to interrupt the CPU as often in order to carry out their tasks. The most common example today is the buffered serial card UARTs (universal asynchronous receiver/transmitter). Another is intelligent serial cards that enable the transfer hundreds or thousands of characters in a single DMA (direct memory access) transfer and the take care of the character-by-character transfer themselves.
Each intelligent I/O card requires a driver for system communications. More accurately, a driver is needed for each operating system that wishes to talk to the card; thus, manufacturers must invest in support of each system. This investment means that most vendors tend to support only the most popular operating systems.
It was recently (meaning a few hours ago) called to my attention that there is an organization called the I2O Special Interest Group that is addressing this problem. Here are a few quotes from their web page:
The objective is to provide an open, standards-based approach ... and provide a framework for the rapid development of a new generation of portable, intelligent I/O solutions.
The I2O model provides an ideal environment for creating drivers that are portable across multiple operating systems and host platforms.
The I2O model is intended to provide a unifying approach to device driver design...
They also pose the question, “Do you see the Unix vendors supporting I2O in their future releases?” and answer it by stating, “SCO is a SIG member and has indicated it will support I2O in future releases of its OS. The SIG welcomes all other Unix vendors to join as well.”
All of this rhetoric sounds like we are all friends, and we will all interoperate happily ever after. However, there does seem to be a catch.
In one of those nice answers about compatibility, we see our first clue that there is a potential problem: “The SIG is set up so that only members and their licensees can design with the specification,....” Even more to the point: “The I2O Specification...is an agreement about the intellectual content and the terms and conditions for how the Specification can be used. Therefore, to make the Specification available to non-members a non-disclosure agreement must be executed.”
I have attempted to contact them for clarification but, so far, they have not returned either my phone call or e-mail.
I'm sure all Linux folks are familiar with the non-disclosure problem. Non-disclosure is why Diamond video boards weren't supported until Diamond changed their mind, and why Linux for the Mac didn't exist for years. To put it another way, you can't comply with both the GPL and a non-disclosure agreement.
Fight—not let someone who claims they are making an open standard get away with an “open to anyone except free software” standard. The first organization to take action is Software in the Public Interest, the same folks who bring us Debian Linux. I have just received a draft of a proposal for an Open Hardware Certification Program. In this program, vendors will make a set of promises about the availability of documentation for programming the device-driver interface of the specific hardware device.
The idea here is that while the program will not guarantee a device driver is available for a specific device and operating system, it does guarantee that anyone who wants to write one can get the information necessary to do so.
I am sure there will be more on this topic on the Usenet newsgroups, on the web and in the press. If you are a vendor, contact SPI (http://www.debian.org/ will point you in the right direction) for more information on their certification program. If you are a potentially unhappy consumer, check out http://www.io2sig.com/ and let the SIG members know what you think about the exclusion of free software from their open standard and about SPI's effort for real open hardware. Finally, watch the LJ web pages for news on what is happening in this important battle.
Phil Hughes is the publisher of Linux Journal. He can be reached via e-mail at firstname.lastname@example.org.
Fast/Flexible Linux OS Recovery
On Demand Now
In this live one-hour webinar, learn how to enhance your existing backup strategies for complete disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible full-system recovery solution for UNIX and Linux systems.
Join Linux Journal's Shawn Powers and David Huffman, President/CEO, Storix, Inc.
Free to Linux Journal readers.Register Now!
- Google's Abacus Project: It's All about Trust
- Download "Linux Management with Red Hat Satellite: Measuring Business Impact and ROI"
- Back to Backups
- Secure Desktops with Qubes: Introduction
- Working with Command Arguments
- Secure Desktops with Qubes: Installation
- Fancy Tricks for Changing Numeric Base
- Linux Mint 18
- Seeing Red and Getting Sleep
- The Italian Army Switches to LibreOffice
Until recently, IBM’s Power Platform was looked upon as being the system that hosted IBM’s flavor of UNIX and proprietary operating system called IBM i. These servers often are found in medium-size businesses running ERP, CRM and financials for on-premise customers. By enabling the Power platform to run the Linux OS, IBM now has positioned Power to be the platform of choice for those already running Linux that are facing scalability issues, especially customers looking at analytics, big data or cloud computing.
￼Running Linux on IBM’s Power hardware offers some obvious benefits, including improved processing speed and memory bandwidth, inherent security, and simpler deployment and management. But if you look beyond the impressive architecture, you’ll also find an open ecosystem that has given rise to a strong, innovative community, as well as an inventory of system and network management applications that really help leverage the benefits offered by running Linux on Power.Get the Guide