Shallow Thoughts : tags : lca2009

Akkana's Musings on Open Source Computing, Science, and Nature.

Fri, 01 Apr 2011

Bonorong Wildlife Sanctuary and the Tasmanian Devil

[Tasmanian Devil] The LA Times had a great article last weekend about Tasmanian devils, the mysterious facial cancer which is threatening to wipe them out, and the Bonorong wildlife preserve in Hobart which is involved in trying to rescue them.

The disease, called devil facial tumour disease, is terrible. It causes tumours on the devils' face and mouth, which eventually grow so large and painful that the animal starves to death. It's a cancer, but a very unusual one: it's transmissible and can pass from one devil to another, one of only three such cancers known. That means that unlike most cancers, tumour cells aren't from the infected animal itself; they're usually contracted from a bite from another devil.

Almost no Tasmanian devils are immune to DFTD. Being isolated for so long on such a small island, devils have little genetic diversity, so a disease that affects one devil is likely to affect all of them. It can wipe out a regional population within a year. A few individuals seem to have partial immunity, and scientists are desperately hunting for the secret before the disease wipes out the rest of the devil population. Organizations like Bonorong are breeding Tasmanian devils in captivity in case the answer comes too late to save the wild population.

When I was in Hobart in 2009 for Linux.conf.au (which, aside from being a great Linux conference, also raised over $35,000 to help save the devils), I had the chance to visit Bonorong. I was glad I did: it's fabulous. You can wander around and feed kangaroos, wallabees and the ever-greedy emus, see all sorts of rarer Australian wildlife like echidnas, quolls and sugar gliders, and pet a koala (not as soft as they look).


[Greg Irons and devil] But surprisingly, the best part was the tour. I'm usually not much for guided tours, and Dave normally hates 'em. But this one was given by Greg Irons, the director of the park who's featured in the Times article, and he's fantastic. He obviously loves the animals and he knows everything about them -- Dave called him an "animal nerd" (that's a compliment, really!) And he's a great showman, with a lively and fact-filled presentation that shows each animal at its best while keping all ages entertained. If you didn't love marsupials, and particularly devils and wombats, before you come to Bonorong, I guarantee you will by the time you leave.

[Tasmanian devil tug-o-war]

A lot of the accounts of devil facial tumour disease talk about devils fighting with each other and spreading the disease, but watching them feed at Bonorong showed that fighting isn't necessary. Tasmanian devils feed in groups, helping each other tear apart the carcass by all latching onto it at once and pulling. With this style of feeding, it's easy to get bitten in the mouth accidentally.

[ferocious killer Tasmanian devil] Of course, I have a lot more photos from Bonorong: Bonorong Wildlife Park photos.

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[ 09:48 Apr 01, 2011    More travel/tasmania | permalink to this entry | comments ]

Fri, 06 Feb 2009

Widescreen laptop for presentations

I've written before about how I'd like to get a netbook like an Asus Eee, except that the screen resolution puts me off: no one makes a netbook with vertical resolution of more than 600. Since most projectors prefer 1024x768, I'm wary of buying a laptop that can't display that resolution.

(What was wrong with my beloved old Vaio? Nothing, really, except that the continued march of software bloat means that a machine that can't use more than 256M RAM is hurting when trying to run programs (*cough* Firefox *cough) that start life by grabbing about 90M and goes steadily up from there. I can find lightweight alternatives for nearly everything else, but not for the browser -- Dillo just doesn't cut it.)

Ebay turned out to be the answer: there are lots of subnotebooks there, nice used machines with full displays at netbook prices. And so a month before LCA I landed a nice Vaio TX650 with 1.5G RAM, Pentium M, Intel 915GM graphics and Centrino networking. All nice Linux-supported hardware.

But that raised another issue: how do widescreen laptops (the TX650 is 1366x768) talk to a projector? I knew it was possible -- I see people presenting from widescreen machines all the time -- but nobody ever writes about how it works.

The first step was to get it talking to an external monitor at all. I ran a VGA cable to my monitor, plugged the other end into the Vaio (it's so nice not to need a video dongle!) and booted. Nothing. Hmm.

But after some poking and googling, I learned that with Intel graphics, xrandr is the answer:

xrandr --output VGA --mode 1024x768
switches the external VGA signal on, and
xrandr --auto
switches it back off.

Update, April 2010: With Ubuntu Lucid, this has changed and now it's
xrandr --output VGA1 --mode 1024x768
-- in other words, VGA changed to VGA1. You can run xrandr with no arguments to get a list of possible output devices and find out whether X sees the external projector or screen correctly.

Well, mostly. Sometimes it doesn't work -- like, unfortunately, at the lightning talk session, so I had to give my talk without visuals. I haven't figured that out yet. Does the projector have to be connected before I run xrandr? Should it not be connected until after I've already run xrandr? Once it's failed, it doesn't help to run xrandr again ... but a lot of fiddling and re-plugging the cable and power cycling the projector can sometimes fix the problem, which obviously isn't helpful in a lightning talk situation.

Eventually I'll figure that out and blog it (ideas, anyone?) but the real point of today's article is resolution. What I wanted to know was: what happened to that wide 1366-pixel screen when I was projecting 1024 pixels? Would it show me some horrible elongated interpolated screen? Would it display on the left part of the laptop screen, or the middle part?

The answer, I was happy to learn, is that it does the best thing possible: it sends the leftmost 1024 pixels to the projector, while still showing me all 1366 pixels on the laptop screen.

Why ... that means ... I can write notes for myself, to display in the rightmost 342 screen pixels! All it took was a little bit of CSS hacking in my HTML slide presentation package, and it worked fine. Now I have notes just like my Mac friends with their Powerpoint and their dual-head video cards, only I get to use Linux and HTML. How marvellous! I could get used to this widescreen stuff.

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[ 21:12 Feb 06, 2009    More linux/laptop | permalink to this entry | comments ]

Wed, 04 Feb 2009

Tasmania Photos

I still haven't finished writing up a couple of blog entries from bumming around Tasmania after LCA2009, but I did get some photos uploaded: Tasmania photos. Way too many photos of cute Tassie devils and other animals at the Bonorong wildlife park, as well as the usual collection of scenics and silly travel photos.

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[ 14:49 Feb 04, 2009    More travel/tasmania | permalink to this entry | comments ]

Fri, 23 Jan 2009

LCA 2009: Friday, the last day

The conference is over! Amazing how quickly a week passes.

Simon Phipps warmed us up with a very good keynote, full of inside jokes and knowledgeable quips indicating he knows the community even if he is a Sun guy.

Matthew Wilcox had some good tips on improving performance on solid state disks that I know will keep Dave busy for a while (I got him a small laptop SSD for his birthday and he's been enjoying it quite a bit -- it's hugely less power intensive and much faster for most operations than the regular disk it replaced). Apparently a lot of his advice will only work on snazzy high-end IBM SSDs, not the cheap ones like netbooks have or like Dave has, but some of them may be helpful anyway. Dave is trying the suggestion of using no I/O scheduler, echo "noop" > /sys/block/sda/queue/scheduler -- apparently there's a lot of crap the scheduler has to traverse that isn't noticable when the drive is seeking all the time, but on an SSD that doesn't need to seek, it can make a big difference. Also, apparently ext4 or btrfs (still under development) have some enhancements that help with SSD performance.

I went to Paul Fenwick's talk (Awesome Things You've Missed in Perl) even though I'm not a Perl hacker ... I know by now that Paul will always have something fun, and indeed he did, including a live demo of a bot that plays Minesweeper. The "awesome things" were indeed pretty cool, and I even found myself tempted to check out Perl again, especially for the new smart regular expression and grammar syntax (you can name parts of regular expressions then define grammars based on them -- very nice!)

Matthew Garrett had entertaining stories on power management, though not a lot of practical advice. Summary: power management sucks, maybe it'll get better some day; users shouldn't be forced to predict their use patterns in order to optimize power usage; video wastes a ton of power, like higher-than-necessary refresh rates when the user is merely viewing static images on an LCD that doesn't need much refreshing.

Then it was lunchtime -- time for the Great Shaving, where Linus shaved Bdale's beard as part of the enormous charity deal (something between $35,000 and $40,000 -- the count still isn't finished yet) toward saving the Tasmanian Devil. Bdale shared some of the emails from his wife (with her permission) and they were pretty funny, as was

"Geek My Ride" (Jonathan Oxer and Jared Herbohn or "Flame") had an entertaining presentation full of successful and impressive demos (we didn't see the actual cars -- those will be at Open Day tomorrow, apparently). I didn't see the whole presentation because I was fiddling around with an idea for a lightning talk, but I saw enough to get the idea.

Kevin Pulo's "Fun with LD_PRELOAD" was indeed fun. He had quite a few examples of existing LD_PRELOAD hacks as well as a detailed example of how to make a custom preloaded library. It's quite a bit more elaborate than I realized, but certainly do-able and something I've been meaning to experiment with for quite a while.

Then, sadly, it was time for the closing ceremonies, including lightning talks (I worked up the nerve and participated, though my laptop didn't behave and wouldn't talk to the projector -- weird how xrandr sometimes works and sometimes doesn't). And then the closing announcements: next year's LCA will be in Wellington, NZ. The Great Shaving had made the Hobart afternoon news, and someone brought in a tape of it. The funniest thing was that they focused on Bdale and the donation but never mentioned the guy who was doing the shaving (some unassuming guy named Linus).

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[ 03:35 Jan 23, 2009    More conferences/lca2009 | permalink to this entry | comments ]

Thu, 22 Jan 2009

LCA 2009: Thursday

The highlight of Thursday morning was a filler: one of the speakers had to cancel, so Paul Fenwick filled in with a combination of two short talks: "The Art of Klingon Programming" and "What's new in Perl 5.10?" I'm not a Perl programmer (at least not when I have a choice) but his talks were entertaining and even educational. What struck me most was that showmanship and humor don't have to detract from technical content. I'd had a discussion the previous day about the balance of offering lots of technical content versus entertaining the audience and not overwhelming them. Most technical talks are either dry, content heavy and so jam packed with information that you can't possibly remember everything, or lighter weight and glitzy but with not much real technical content and a "watered down" feeling. Paul's Klingon talk was one of the most content-full presentations I've seen at a conference, with lots of code examples, yet it kept the audence laughing, listening and grokking (to mix SF metaphors) all the way through. Showmanship can make it easier, not harder, to remember technical content.

In the afternoon, I'd been very much looking forward to the Arduino tutorial (Jonathan Oxer and Hugh Blemings) but it was a bit of a disappointment. The acoustics of the room and the handheld microphone, combined with the interactive nature of the presentation, meant that I could barely understand a word High Blemings said, and only some of what Jon Oxer said. (I've heard Jon Oxer talk before and never had trouble, so I primarily blame the room.)

Partway through, I skipped out to go check Donna Benjamin's "The Joy of Inkscape." It had been moved from its original lecture hall to a much smaller room with tables. The smaller room was Standing Room Only, a raucous and enthusiastic bunch who (the sitting ones, at least) were nearly all tapping away on laptops exploring either the demo Donna was showing or other Inkscape projects.

It was clearly a hugely successful and fun tutorial and I wanted to stay, but I couldn't find a place to sit where I could both see the screen and hear Donna, so I made my way back to Arduino. The second half, when they demoed various interesting sensors and a few unusual Arduino applications, was better than the first. But talking to folks later, a number of us were surprised because we expected a more interactive tutorial (the prep had encouraged us to bring or buy Arduino hardware).

The hot talk of the day was one I missed, after the tea break. I went to a talk on Spring, a robotics library (Clinton Roy), which was interesting enough and certainly popular (lots of people sitting by the door because all the seats were full) but afterward all I heard was people enthusing about Jeff Arnold's amazing Ksplice talk. He demonstrated a system of updating kernels in place, with no reboot required. People couldn't say enough about the talk, and I'm looking forward to downloading the video and seeing what I missed.

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[ 13:41 Jan 22, 2009    More conferences/lca2009 | permalink to this entry | comments ]

Wed, 21 Jan 2009

LCA 2009: Wednesday

Wednesday started with a keynote by Tom Limoncelli that was, frankly, disappointing. A lot of it was specific to enterprise sysadmins (including a set of "homework" for all the new directives you're going to implement in your IT department) and the rest was, well, nothing special.

The first regular talk I heard was Keith Packard, describing advances in X (and related graphical desktop software) over the past year. Surprisingly, there actually have been a lot of advances. Chief among them is GEM, a system for sharing data efficiently between X and the kernel to avoid all the horribly inefficient copying that's always happened in the past. It all sounded very promising except that if I understand him correctly, none of this works on graphics cards, only on integrated Intel graphics. A nice step, but until it works everywhere I'm not sure it's really a solution.

But Keith was overshadowed by his coworker, Carl Worth, who spoke next, giving a lively and interesting discussion of the architecture of graphics on Linux, including the many ways control might flow depending on which libraries are in use and the capabilities of the graphics card/chipset are. Better, he enumerated the many ways of tracing the execution of the various graphics layers -- gtk, cairo, X, mesa etc. -- and I'm looking forward to downloading his slides to get the list of debugging commands. This may also be the first talk I've seen to use GIMP as a presentation system. (He only used it for one slide, where he drew and labelled new codepaths people have proposed to get around graphics bottlenecks.

My tutorial (on Firefox/Mozilla hacking) was after lunch. I was fairly happy with it. The audience had a lot of questions, the slides I had hoped were funny got laughs, and the time worked out -- I had to rush through the last handful of slides because of the amount of audience questions and discussion, which is much better than ending early because no one was interested.

Jonathan Corbet's talk on the Linux Development Process mostly fairly basic details I already knew (what the difference kernel trees mean, how subsystem maintainers act as gatekeepers, why it's better to maintain code in the mainline kernel tree than separate code) but his talks always have nuggets of interest and relevant stories, with Linus sitting in the audience to add another perspective. The talk ended with some good advice on how to get started in kernel development: review code, and (in a quote from Andrew Morton) "try to make the kernel work well on every machine you have access to."

Wednesday night's Penguin Dinner was spectacular. The dinner was fairly spectacular itself (a huge and varied buffet), but the really impressive part was after dinner. We saw a short presentation on the plight of the Tasmanian devil (the largest marsupial carnivore after the extinction of the Tasmanian "tiger", or thylacine, in the early 1900s). The devil is threatened due to a transmissible cancer that causes horrible facial tumors which are invariably fatal. Then the charity auction began, led by Rusty Russell. At auction was one item: a large format numbered print of a beautiful, award winning waterfall photograph by Karen Garbee. Bidding was spirited and rose very quickly into the thousands of dollars, at which point things got complicated, with coalitions of multiple people bidding, other people offering matching offers under certain conditions, other items (such as a GEEK license plate registered in Queensland) being added to the photograph. In the end the winning bid was $10,500 (which amounts to something over $36,000 when various matching funds are included) on condition that Linus shave Bdale's beard.

Poor Bdale! The beard suits him and he's had it since 1982. But it will come back, and the Tasmanian devils won't if the cancer drives them to extinction.

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[ 14:32 Jan 21, 2009    More conferences/lca2009 | permalink to this entry | comments ]

Tue, 20 Jan 2009

LCA 2009 Tuesday

I missed a lot of the miniconf talks on Tuesday because I wanted to make some last-minute changes to my talk. But I do want to comment on one: Simon Greener's talk on "A Review of Australian Geodata Providers." Of course, I'm not in Australia, but it was quite interesting to hear how similar Australia's problematic geodata siguation is to the situation in the US. His presentation was entertaining, animated and I learned some interesting facts about GPS and geodata in general.

And Dave and I got another good astronomy opportunity with the dark skies at Peppermint Bay at the Speakers' Dinner. Despite occasional intrusive clouds we managed to get a great view of the Large Magellanic Cloud and a decent view of the small one, as well as eta Carinae and the star clouds between Crux and Carina. Pity I'd forgotten to bring my thumpin' travel optics that I'd been using the previous evening: a 6x20 monocular.

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[ 16:15 Jan 20, 2009    More conferences/lca2009 | permalink to this entry | comments ]

Mon, 19 Jan 2009

LCA 2009 Monday

On day one of LCA 2009, I divided my time between the LinuxChix and Kernel miniconfs.

In the morning, Paul McKenney, in "Why is parallel Programming Hard?", discussed some of the background of parallel programming research, then gave an entertaining demonstration of instruction overhead using a roll of toilet paper. Each square represented one clock cycle -- he estimated there were a few hundred clock cycles in the full roll -- and he had audience members unroll the roll carefully, passing it from one person to the next. It took a long time.

Over at the LinuxChix miniconf, Jacinta Richardson gave a wonderfully entertaining (and useful) talk "On Speaking". She explained how to hack audience members' brains, particularly the corpus callosum and the hippcampus, by using emotion, visual images and suspenseful stories to give your audience whole-brain entertainment.

After Jacinta's talk we spent some time going around the room introducing ourselves, and speakers got a chance to plug their upcoming talks.

I skipped the panel on Geek Parenting (not being a parent) to go back to the kernel miniconf's "Problem Solving Hour". Questions involved network performance, solid state disk performance, how to debug crashes, tracing (the moderator commented that if you're thinking of getting involved in the kernel effort but aren't quite sure what to do, there's a huge need for better tracing and performance analysis tools), solid-state disks (someone plugged the talk on that subject on Friday) and similar interesting topics.

I asked about an overheating problem I've been having with my laptop. I mentioned that even in single-user mode, the CPU temperature keeps going up, so I was pretty sure it was a kernel and not userspace issue. Matthew Garrett said that a lot of drivers are optimized for a normal use case -- meaning X -- and may work very poorly in text mode. You can have something that's overheating in single-user mode, then you start X and a bunch of power management systems kick in and the temperature actually goes down. So how do you figure out what's causing a temperature problem? Open up the laptop when it's hot, poke around then figure out what's hot. Then debug that component.

Lunch was a lovely BBQ provided by Google.

After lunch, Matthew Garrett, in "How I learned to stop worrying and love ACPI", was entertaining, as all his talks are. I'm not sure I actually learned much in the way of practical advice for helping ACPI work better on my machines, but at least I learned lots of new ways in which ACPI sucks more than I ever realized.

Then it was back to LinuxChix for a workshop on getting schoolgirls more interested in IT. We saw short presentations from the four workshop leaders, then split into groups -- our group went outside and sat in the hazy sunshine and talked about how to get girls, teachers, parents and school IT staff on board.

After tea, all the LinuxChix groups reported back on the discussions and there was a full-room discussion on how to get involved with educational programs like that. Then we ended with lightning talks; I got roped into giving one, so I didn't take notes on the rest, but they were all fun and interesting.

Then in the evening, after dinner, we found a spot somewhat sheltered from the lights of the hotel for some quick astronomy before bed. The sky was hazy and picking up lots of sky glow from a light beam shining from the hotel, but fortunately the sky around the Southern Cross was clear. We found both the Large and Small Magellanic clouds, as well as Eta Carina and some other clusters around the Southern Cross. A lovely view, unmatched by anything I saw from around Sydney or Melbourne. Tasmania definitely wins for stargazing!

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[ 04:17 Jan 19, 2009    More conferences/lca2009 | permalink to this entry | comments ]

Sat, 17 Jan 2009

Please wait, we're rebooting the plane

I'm in Tasmania! I still love the sound of that -- it sounds so exotic.

But this is just a short entry, partly to make sure my feed is working for the LCA 2009 planet, and partly to write about an experience on the outbound flight.

Planes never seem to leave the gate on time. There's always something. This time, the problem was that some of the reading lights in First and Business classes weren't working properly. So they fiddled with them for a while. Dave joked "They'll probably have to reboot the Windows computer that's running the lighting system." "Ha ha," I laughed.

Then came the next announcement:

Uh, ladies and gentlemen, we've determined that it's not the lights themselves that are causing the problem. It seems to be a software problem with the computer running the system. So we're going to shut down for about two minutes and see if that fixes the problem.

How do you reboot a lighting controller on a plane? It turns out, what you do is -- shut down the entire plane. Shut the engines off, cutting all power to the entire plane -- no lights, no fan, even the emergency lights went out after a few seconds.

They stayed off for about three and a half minutes (not two) and then took a bit over half a minute to come back up, bit by bit.

And indeed, that fixed the problem. Dave commented afterward, "That's like rebooting your PC by cutting the main breaker to the entire house."

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[ 21:54 Jan 17, 2009    More conferences/lca2009 | permalink to this entry | comments ]