Understanding the History of Linux

Tero Roponen

In the late 1990's the Linux kernel started to support more than
one CPU. For the needed locking the BKL (Big Kernel Lock) was
introduced. Today the kernel supports 4096+ CPUs with a
fine-grained locking but there are still some subsystems that
can't handle it because of still using the BKL. The difficult and
risky process of getting rid of that old progress-hindering
baggage has been under way for almost ten years but still isn't
complete.

In this presentation I will give you a short overview of the
history of Linux development. The focus is on the design decisions
made in the past that in their own time have been good but have
since turned out to be problematic. Fundamental reasons for some
of these problems are discussed and some ways to prevent the same
kind of problems in the future will be given.