The last MP step

There’s only one multiprocessing bottleneck left in DragonFly: vm_token.  Matthew Dillon’s working on removing it, and he’s been testing his initial results on a 4-core machine and a 48-core machine, using heavily parallelized buildworlds to test concurrency.  He’s posted the results, showing an initial speedup of up to 30%.  This definitely isn’t going to make it into 2.12, but it’s looking good already.  Keep in mind these are improvements on top of the performance graphed here yesterday.

More performance graphing

Venkatesh Srinivas sent along a graph of his nmalloc testing that shows mysql threading performance on DragonFly, from slightly over a year ago.  Both graphs were done on a 4-core system, though I don’t know if the specs are comparable, so the curve is important.  Look at the just-posted curve for comparison.  That’s how much things have improved.

In fact, here’s a cheesy overlay, cropping the more recent results and laying the old ones on top of it.  The black lines are the year-ago performance, and the colored lines are the performance now.

Improved DragonFly threading performance

Performance curve for DragonFly 2.12

Samuel Greear has graphed out the performance of both MySQL and Postgres on DragonFly 2.12 as you add threads.  There’s a very nice correlation on performance and number of cores.  For comparison, there’s this old test from 2007 which shows uniprocessor performance to be good but not improved by adding cores.  The tests were on completely different hardware, so the actual curve of the graph is the telling point.

As he points out in his post, excellent multiprocessor performance is arriving on DragonFly, without any catastrophic shifts or destabilizing changes.

Lazy Reading for 2011/09/25

This week’s Lazy Reading just built itself up quickly; autumn arrives in the northern hemisphere and suddenly a lot more activity starts going on.

There are four ways to deal with system damage: 1) reliability, 2) redundancy, 3) repair, and 4) replacement.

More blogbench benchmarks

Francois Tigeot has done another set of benchmarks using blogbench to test reading and writing under different DragonFly versions, plus some OpenIndiana benchmarks just to mix it up.  Writing performance seems to have drastically improved between DragonFly 2.10 and 2.11.

His post has an attached PDF with, of course, graphs.  This site has previously mentioned other not-really-comparable disk testing performed by Francois.

Lazy Reading for 2011/09/18

I might have a job open at my workplace soon, for a junior admin/support/network role.  (Department is too small for narrowly defined roles…)  I’ll post about it here if it happens.

  • libguestfs, ‘tools for accessing and modifying virtual machine disk images’.  (via)  I can think of a lot of places that could be useful.
  • I did not know this, but FreshBSD tracks DragonFly commits, along with the commit logs of most (all?) other BSDs.
  • Bruce Perens set up a “Covenant” license for the HPCC database (powers Lexis/Nexis) that is actually pretty good at allowing something to be both open source and commerical; the ‘release notes‘ talk about it.
  • I agree with these sentiments on hiring exactly.  If you really like what you do, you don’t just do it at work.  (The author’s followup.)  Putting it in a more positive light, showing work on open source, outside of your workplace, is a great thing to add to your resume.  Never trust the graphic designer with sloppy handwriting.
  • The majority of the 10 most stable web providers out there are running a BSD.  FreeBSD, in this case.  (via, via(why does Twitter make it so hard to link to things?  Cause they don’t want you reading the web – just them.)
  • Usenet, as of 1981, with posts arriving in actual time (-30 years).  (via)  You can even use a NNTP reader to connect.  Similar to but not as colossal as telehack, mentioned here before.
  • DragonFly deployment.
  • I am so proud of myself for coming up with this joke.

Your unrelated comics link of the week: Saturday Morning Breakfast Cereal.  It used to mostly be violent and nonsensical, but recent strips are excellent, like this one or this.