At The Linux Foundation‘s Open Source Summit North America in Vancouver, Linus Torvalds, Linux’s creator, and Dirk Hohndel, VMware VP and chief open source officer, had a wide-ranging conversation about Linux security, open-source developer, and quantum computing.
Torvalds would really like his work to get back to being boring. It hasn’t been lately because of Intel’s CPU Meltdown and Spectre security bugs. The root cause behind these security holes was speculative execution.
In speculative execution, when a program does a calculation, which might go several ways, the processor assumes several results and works on them. If it’s wrong, it goes back to the beginning and restarts with the correct data. Because CPUs are so fast these days, it’s much quicker to do this than to have the hardware sit idle waiting for data.
Torvalds “loves speculative execution. CPUs must do this.” But, Torvalds is annoyed that “people didn’t think about the problems of taking shortcuts with speculative execution. We knew speculative work that wasn’t used had to be thrown away.” It wasn’t. That problem is now baked in most modern processors. The long-term fix is a new generation of Intel CPUs.
Read more at ZDNet