This post shows a standard PostgreSQL benchmark on a big machine (2 cpus * 6 cores/cpu * 2 hardware threads/core, 96GB RAM) and the news is that Dragonfly is approaching FreeBSD's performance (while hopefully being more flexible/secure due to the microkernel design).
As an aside, Scientific Linux handily destroys both FreeBSD and DragonflyBSD in localhost benchmarks, but crashes rather a lot. (This seems odd, but the focus is on the DragonflyBSD / FreeBSD comparison anyway.)
Sounds like a rather hard crash to me.
Remember this is a narrow benchmark of multi-core scalability under a SQL load. It's not particularly useful as evidence in OS flames, and the goal isn't to see "how much faster" Linux is, but rather to characterize areas where Dragonfly needs work.
(I will admit I was surprised at how much better Linux did at the heavy-SMP side of the graph though. Edit for clarity: I'm not at all surprised that Linux does well; I live in that world too. I'm surprised that it does so much better than the BSDs. At the right edge of the graph, Linux is still flat where the other kernels are dropping fast due to overhead, and Linux is doing 3x-4x better. That's surprising.)
Benchmark results from the above thread: http://leaf.dragonflybsd.org/mailarchive/kernel/2011-11/pdf0...
From http://wiki.openindiana.org/oi/Frequently+Asked+Questions/:
Is OpenIndiana a "fork"?
Kind of.
OpenIndiana aims to be binary and package compatible with the upcoming Solaris 11 and Solaris 11 Express, and most of the operating system is built from source code that Oracle continues to make available. So in some ways, our relationship is similar to the way the CentOS project tracks Red Hat Enterprise Linux.
However there are differences, for example we intend to use illumos in place of the official OS/Net consolidation which is no longer open source, and we also intend to provide improvements on top.
What is the relationship between OpenIndiana and illumos?
OpenIndiana provides a complete, ready-to-use operating system (distribution) similar to the former OpenSolaris distribution.
We run far bigger PostgreSQL DBs than this, and we've never had a RHEL crash. Ever.
Maybe there's something wrong with the hardware?
Additionally, if fsync = on in this test, then you're mixing a file system test with a database test.
Which is reasonable, given that file systems of any reasonable performance level (read: not user-space file systems) still tend to be bundled with one or at most a handful of reasonable kernel implementations. Turning fsync off would highlight some interesting bottlenecks, but I'm not sure if that makes for the most sensible comparison either. Not only is the fsync/checkpointing period of a database's operation important to model in a broad-spectrum benchmark, but some amount of file system coupling is unavoidable. One example is metadata syscalls to the file system, which have been a point of poor concurrency before[0]
I agree the fsync = off benchmark would be interesting, but I don't think it's fair to say that the information of an fsync = on test is a) less valuable/clearly improperly performed b) necessarily indicative of the most important bottlenecks for database workloads. A kernel that takes a huge lock during fsync(), for example, should be penalized for it.
Finally, fsync = off doesn't accomplish the stated goal of "independence" from the file system. And as seen in Robert Haas's post, non-fsync file system calls can be the problem in high concurrency situations.
[0] http://rhaas.blogspot.com/2011/08/linux-and-glibc-scalabilit...
