On Saturday, September 1, 2018, Warner Losh wrote: > > > On Sat, Sep 1, 2018 at 7:50 AM Andy Kosela wrote: > >> >> >> On Saturday, September 1, 2018, Steve Mynott >> wrote: >> >>> >>> >>> On Wed, 29 Aug 2018 at 15:53, Larry McVoy wrote: >>> >>> The BSDs have a less than optimal VM system. Having SunOS opened up >>>> would at least let people see what they are missing. Maybe I have >>>> rose colored glasses on but it was the only kernel that came into >>>> focus for me and you could see the architecture from the code. >>>> Everything else seems like a mess to me. >>>> >>> >>> That may have been true in the late 80s and even early 90s but I'd have >>> thought FreeBSD, NetBSD and OpenBSD would have useable VMs by now. >>> >>> I've vague recollections that these all originally used the VM from Mach >>> which did have problems at first. >>> >> > Yes. CSRG used Mach VM because it was available, not because it was > awesome. The folks at CSRG approached Sun to have them donate their VM to > BSD, and there were serious talks about doing this until the lawyers got > involved and explained that would require a serious write down on their > quarterly report so that nixed the whole thing. > > >> I recall a more knowledgeable friend complaining about FreeBSD VM in 1994 >>> or so. >>> >> > It used to be downright aweful. > > >> I think the latter two use UVM and FreeBSD improved their Mach one (which >>> has a SunOS kvmish API anyway). I've not seen complaints about modern BSD. >>> >> > OpenBSD and NetBSD both moved to uvm. > > >> Wasn't the whole FreeBSD VM rewritten by John Dyson and David Greenman in >> the mid-late 90's? And then further improved by Matthew Dillon. >> >> Unfortunately they are not affiliated with the project anymore. All >> three had exceptional coding skills. >> > > With the exception of David, it's not unfortunate at all. Although they > were good for the project's code, they weren't good for the project. They > didn't work well with others and caused much more grief than the code they > contributed. There comes a time when there's just too much drama and the > rest of the code gets much much better when you aren't always fighting > drama :(. It was a tough decision to make when I was on the core team to > show Dillon the door. One not made lightly, nor without a lot of effort to > work through the issues. In the end, though, we had to part ways. Dillon > has done well with DragonFly, however. > Well, there are certainly as many sides to this story as there are people involved. Same with NetBSD/OpenBSD split. Let's leave it as that as I don't believe we have mentioned people on this list so they can't defend themselves. --Andy