DragonFly kernel List (threaded) for 2011-12
Merry X-Mas and 3.0 release after the holidays - date not yet decided
Hello everyone! First, I apologize for the aborted 2.12 release. We
got as far as rolling it but I decided to make a real push to try to
fix the occassional random seg-fault bug that we were still seeing
on 64-bit at the time.
The seg-fault issue has now been resolved, I posted an exhaustive
synopsis to the kernel@ list just a moment ago. Basically it appears
to be an AMD cpu bug and not a DragonFly bug. We don't have final
confirmation that it isn't a DragonFly bug because it is so sensitive
to %rip and %rsp values that reproducing the environment to test it
on other OSs (even FreeBSD) is difficult, but I'm 99% certain it's an
AMD bug. Add a single NOP instruction to the end of one routine in
the gcc-4.4 codebase appears to work around the bug.
So moving on to rolling an official release...
(1) Through past experience we will NOT do a release during the
holidays! So everyone please enjoy Christmas and New Years!
(2) I would like to call the release 3.0. Why? Because while
spending the last ~1-2 months tracking down the cpu bug a whole lot
of other work has gone into the kernel including major network
protocol stack work and major SMP work. My contribution to the SMP
work was to completely rewrite the 64-bit pmap, VM object handling
code, and VM fault handling code, as well as some other stuff.
This has resulted in a phenominal improvement in concurrency and
in particular concurrent compilations or anything that takes a lot
of page faults. SMP contention was completely removed from the
page fault path and for most VM related operations, and almost
completely removed from the exec*() path.
Other related work has continued to improve mysql and postgresql
numbers as well.
(3) Release date is as-yet undecided. It will probably be mid-February
to end-February in order to synchronize with the pkgsrc 2011-Q4
release and give things time to settle. The release meisters will
be discussing it on IRC.
I will say that there are NO serious showstoppers this time. I'd
like us to take our time and make this the best release we've ever