Performance-oriented development in the commercial computing world

On 30 Oct 2011 at 14:05, Toby Thain wrote: We'd do it at the source level years ago, using a source library program such as UPDATE. It's often the case that so many structures and procedures are shared by routines in the OS, that a full recompile was about as effective as a partial build. An extreme case of compiles taking a long time was when I was doing STAR OS development and the only (convenient) resource was a pair of STAR-1B systems (the only extant ones), that ran at somewhere around 1/1000th the speed of the real thing. They were not intended as standard line products, but rather as development platforms that had the same core (256K words), and attached to standard STAR SBUs and MCU, but were otherwise bit-serial heavily microprogrammed emulators.. A compile of the OS kernel was an overnight job, taking a bit more than 8 hours. That's the kernel, not any of the system utilities. More often than not, the hardware would develop problems and you'd lose a day. You quickly learned that desk-checking everything thoroughly would save huge amounts of time. It was a very frustrating way to work. There were only two other options--beg some maintenance time from the CEs at Livermore, or grab a flight to Minneapolis/St. Paul to use the system at ADL in Arden Hills to recompile. This was quite possibly the worst development environment that I'd ever worked in. --Chuck