LCA: Andrew Tanenbaum on creating reliable systems

Posted Jan 18, 2007 18:15 UTC (Thu) by bcd (guest, #11759)
In reply to: LCA: Andrew Tanenbaum on creating reliable systems by jwb
Parent article: LCA: Andrew Tanenbaum on creating reliable systems

High performance software relies on tricks which are, for the most part, quite unsafe. Your 3D game only works because the GPU is allowed unchecked access to main memory. If you were to start being careful about that access, performance will suffer.

There's always a performance/reliability tradeoff. But if ask the users of *most* systems -- outside of the limited scope of 3D gaming -- you'll find that reliability is more important, as it should be. And we're not just talking about desktop PCs: it's also about the embedded devices that we're all putting more trust into these days.

It's hard to focus on performance first and reliability later -- I've tried this in my own software, and what usually happens is the bug fixes and redesigns to address instability blow away all of the performance gains you started with. It's much easier as a developer to get it right first, and worry about the performance second. Sure, it's a close second, but it's still second.

Tanenbaum's points should be first discussed and debated on their own merits, regardless of performance implications. Do these principles really guarantee higher reliability? Are microkernels the best way to implement these principles? Trying to address performance concerns at the same time only complicates things.