The Background – Linux as a Fast Follower and the Need for Hot Patching
No doubt about it, Linux has made impressive strides in the last 15 years, gaining many features previously associated with high-end proprietary Unix as it made the transition from small system plaything to core enterprise processing resource and the engine of the extended web as we know it. Along the way it gained reliable and highly scalable schedulers, a multiplicity of efficient and scalable file systems, advanced RAS features, its own embedded virtualization and efficient thread support.
As Linux grew, so did supporting hardware, particularly the capabilities of the ubiquitous x86 CPU upon which the vast majority of Linux runs today. But the debate has always been about how close Linux could get to "the real OS", the core proprietary Unix variants that for two decades defined the limits of non-mainframe scalability and reliability. But "the times they are a changing", and the new narrative may be "when will Unix catch up to Linux on critical RAS features like hot patching".
Hot patching, the ability to apply updates to the OS kernel while it is running, is a long sought-after but elusive feature of a production OS. Long sought after because both developers and operations teams recognize that bringing down an OS instance that is doing critical high-volume work is at best disruptive and worst a logistical nightmare, and elusive because it is incredibly difficult. There have been several failed attempts, and several implementations that "almost worked" but were so fraught with exceptions that they were not really useful in production.[i]
In the world of CMOS semiconductor process, the fundamental heartbeat that drives the continuing evolution of all the devices and computers we use and governs at a fundamantal level hte services we can layer on top of them is the continual shrinkage of the transistors we build upon, and we are used to the regular cadence of miniaturization, generally led by Intel, as we progress from one generation to the next. 32nm logic is so old-fashioned, 22nm parts are in volume production across the entire CPU spectrum, 14 nm parts have started to appear, and the rumor mill is active with reports of initial shipments of 10 nm parts in mid-2016. But there is a collective nervousness about the transition to 7 nm, the next step in the industry process roadmap, with industry leader Intel commenting at the recent 2015 International Solid State Circuit conference that it may have to move away from conventional silicon materials for the transition to 7 nm parts, and that there were many obstacles to mass production beyond the 10 nm threshold.
But there are other players in the game, and some of them are anxious to demonstrate that Intel may not have the commanding lead that many observers assume they have. In a surprise move that hints at the future of some of its own products and that will certainly galvanize both partners and competitors, IBM, discounted by many as a spent force in the semiconductor world with its recent divestiture of its manufacturing business, has just made a real jaw-dropper of an announcement – the existence of working 7nm semiconductors.