It was certainly needed over time but capabilities from things like RCU out of Sequent weren't that important in the 2000 timeframe. And a lot of IBM's contributions didn't come online until the v4 kernel.
None of this is to minimize IBM's contributions to Linux over time but I'd argue pretty strongly that IBM's endorsement of Linux for enterprises in January 2000 is what really moved the needle in the short run.
Here's what one of the people most directly involved told me a few years ago:
"By the late 90s, it was clear that Linux was becoming more and more important. And we formed a major task force to see to what extent IBM should embrace Linux and this happened in 1999. And the task force came back and said, we absolutely should embrace Linux, that it was going to be an incredibly important part of computing, that we should embrace Linux across all of IBM's offerings. And that IBM should become a major supporter of Linux.
"And I still remember very well in December of ‘99, I called Sam Palmisano, the head of IBM Systems Group. And I said, Sam, the task force recommends that we should embrace Linux. And Sam said, okay, Irving, we will do that. But you have to now come over and run an IBM Linux initiative. And I said to Sam, okay, we were pretty much done with our internet strategy. So I was no longer needed to run the Internet division And I said to Sam, when do you want to announce it? And Sam said, how about now? And I said Sam. It's the Christmas holidays. Maybe we should wait until the new year. And in the second week of January of 2000, we made a major announcement saying that IBM would embrace Linux across all of these offerings. And in fact, later that month in January of 2000, I gave a keynote at LinuxWorld, which was taking place in the Javits Center in New York City, about IBM’s Linux initiative.
"At some level, the rest is history."
