Posting but not reading mailing lists

The old mailing list software for @dragonflybsd.org mailing lists, bestserv, apparently allowed people not subscribed to a list to post to it, after answering a confirmation message for each message posted.

The closest way to duplicate that for Mailman is to sign up for the list you want, and then turn off mail delivery for your email address in the config page for that mailing list.  This won’t affect a lot of people, since most people want list output in their mailbox, but there’s at least a few I’ve fixed that way.

A flurry of fixes and scheduler improvements

The combination of Mihai Carabas’s successful Summer of Code work on the scheduler and the recent Postgres benchmarking got Matthew Dillon to start thinking about making UNIX domain sockets work better, a shortcut around the buffer cache, scheduler improvements and then a new default scheduler, along with a change in idle CPU behavior.  The best place to understand all the changes is in his long post to users@.

We should have benchmarks soon to show the performance improvements from all this.

SYSV shared memory vs. mmap

Francois Tigeot benchmarked the recent Postgres 9.3 release.  Postgres apparently switched to using mmap instead of SYSV shared memory, and Francois has done this to show the performance differences.  (view the PDF in his post.)  Of course, work has continued since this was posted, so there should be new numbers soon, and new changes I’ll document in a future post.

I haven’t found a reference to the exact decision Postgres made on how to handle memory; please post a link in comments if you know a good source.

Lazy Reading for 2012/09/16

Yay!

  • What will you have: tea or chai?  Mapping out all the names for tea around the world.  I love etymology and tea, and I know there’s some tea drinkers reading…  (via)
  • Speaking of tea, this London universal tea device sounds awesome.  (via)
  • Uncle Miod’s machineroom.  There’s some pictures of some old hardware buried in there that was incredibly expensive when it first came out…   (via)
  • This security issue is interesting because it’s a new kind of problem, but also depressing because it’s a new kind of problem.  (via)
  • Apparently a packaging system is always a good idea.  (explanation)
  • A patient explanation of /usr/local and a bit of UNIX file system history, too.  (via)
  • The history of Unix from where it happened, Bell Labs.  I’m pretty sure I haven’t linked to that before.  Interesting trivia note: playing the original Space Travel game in 1969 cost $75 for the computer time.(via)

Your unrelated link of the week: Top Shelf is having their annual $3+ comics sale.  There’s some really good books for cheap, there.  Of special note: From Hell, about Jack the Ripper, drawn by my favorite artist.  Wizzywig, mentioned here before as a fictional mishmash of real stories and rumors about hackers and BBSes and other things people need to be a certain age to remember.  The Ticking, drawn by Renée French, whose art should be familiar to fans of Plan 9 or Go.

NYCBUG, RSS, and SMPng

NYCBUG, the NY BSD user’s group, has an RSS feed for their speaker events, found via Dru Lavigne’s always useful BSD Events twitter.  The next event at the start of October is a talk about SMPng in FreeBSD.  Given that it was the project that in part led to the creation of DragonFly, I’d like to hear about it.  (and even better, have someone more qualified than I compare and contrast that approach with what’s in DragonFly.)

Experimental pmap optimizations

Matthew Dillon has created an experiment: shared page table mappings.  It’s controlled by a sysctl, since it’s still experimental.  The real-world effect is reducing the number of memory faults as a process uses up memory, and decreasing the overall memory usage.  The obvious benchmark is Postgres speed; this makes the initial expansion of memory usage much less of an drag on speed due to a high memory fault rate.

If all this mention of faulting sounds like a problem, remember memory faults on BSD are normal; that’s how programs indicate they need more memory space by causing a fault.  This is in contrast to Linux, where memory is allocated a different way.  Or at least, that’s my understanding.  (If you know better, please comment.)

Lazy Reading for 2012/09/09

Whee!

  • deadweight, “Find unused CSS selectors by scraping your HTML”.  I’ve needed something like this for years.  (via)
  • The same sort of thing for pkgsrc: pkg_leaves.  Worth running at least yearly, or at least before any significant pkgsrc upgrade.  There’s no point in updating a package you don’t use or need.
  • GNU Coreutils cheat sheet, plus the instructions to make it.  There’s other cheatsheets linked in the article that may be useful.
  • Compiler benchmarks, comparing gcc and clang versions.  For a complete benchmark, I’d want to compare what number of programs build with each, too.  (via ftigeot on #dragonflybsd)
  • When ‘your mom’ and Unix jokes collide.
  • Distraction-free writing with Vim.  (via)
  • Also, there’s a “Modern Vim” book on the way.  Will it be good?  I have no idea; I don’t know of any prior books by the author or who the publisher is.  Those facts might help.
  • For a known author and publisher, here’s a status report on Absolute OpenBSD, 2nd Edition.  If you don’t know what a BOFH is from his last sentence, read the original stories.
  • Quadrilateral Cowboy, a cyberpunk hacking game that actually involves non-boring programming and not just a pipe-matching game under the guise of hacking.
  • While I’m linking to games, GUTS, sorta like Diablo but more… roguey?  It’s turn-based.  Also, an excuse to use the roguelike tag.
  • 4 UNIX commands I abuse every day.  Having done a fair amount of Perl programming, I am entertained by having side effects being the intended goal.  Also, the author pays attention to what runs on BSD.  (via)
  • Disks lie. And the controllers that run them are partners in crime.”  Marshall Kirk McKusick describes just how hard it is to know when your data has really made it from memory to disk.  (via)

Your unrelated link of the week.  Dubgif.  Random animated gifs and dubstep clips.  Sometimes it doesn’t work, and sometimes it’s perfect.  (via)  If that’s too random, there’s also this .