It’s kind of hard to remember when Linux last had a version upheavel like the first release candidate of Linux 4.0…. sorry, no I tell a lie, it was 22 July 2011 when Linus finally pulled the handle on Linux 2.x and released Linux 3.0. That was quite a change when you consider that the 2.x version had arrived in 1996, with 2.6 turning up in 2003 and incrementing away all the way to 2.6.39 in 2011. The switch to 3.x has now seen 19 releases over the four years so switching version numbers up to 4.0 should be a no-brainer.
It was that 3.0 version change which woke people up from the Linux 2.x problem, where scripts assumed Linux versions began with a 2 and, lets be honest, it wasn’t really a problem. If you have scripts which are assuming 3.x version numbers on your Linux builds, find the person who wrote them and sit them down for a “conversation” because there’s no way that that kind of assumption is excusable after only four years. For 2.x, there was fifteen years of heritage, not so for 3.0.
Don’t read too much into the use of a poll to pick the new version number.
... after extensive statistical analysis of my G+ polling, I've come to the inescapable conclusion that internet polls are bad.
That’s Linus’s git commit comment as he turned over the version numbering and labelled the release “Hurr durr I’ma sheep” – the other option in a “Please ignore this poll” poll. “Who can argue with solid numbers like that? 5,796 votes from people who can’t even follow the most basic directions?” says Linus. The 4.0 vs 3.20 poll had a bigger turnout but the majority was so slim “it could be considered noise.”.
What’s in 4.0 RC1? It’s yet another incremental update of Linux. In his LKML posting, Linus points out his favourite features are ” actually some vm cleanups, where this release is getting rid of the largely unused non-linear remapping code (replaced with just emulating it with lots of smaller mappings) and unifies the
NUMA and PROTNONE handling for page tables”. For others, the live patching system thats being introduced may allow future kernel problems to be fixed without a reboot; here’s the commit.
Apart from that, a small typical update which would have passed relatively un-noticed if it had been a 3.20. So, it’s Linux 4.0 RC1 and that’s Numberwang!