Jun 162009
 

Recent pickings. Some of them very rarely updated, some constantly:

  • Speakeasy, Wall Street Journal’s culture blog reaches wide and occasionally deep.
  • Linuxpundit, occasional insights into embedded Linux.
  • Rädyn Rykäisy, Seppo Räty, the finest example of finnish speech has his say about the world of sports.
  • Ben Schott (yeah, the one of the Miscellanies-fame) expands readers’ vocabulary.
  • Festarit, helsingin sanomat once again tours the summer festivals.
  • eat.fi, the blog of the finest finnish sybaritic social network is updated very irregularly.
Sep 192007
 

Here we go again. It’s so hard to hold back the stream of links.

M.C. Escher's Relativity as imagined in Lego
Jun 052007
 

Something off the side of the trawler.

  • Yes, the whole american nation feels the pain of the wrong guy nearing Hank Aaron’s home run record.
  • World Domination 201, a surprisingly lucid document from the lately very frothy keyboard of ESR.
  • Songbird, an open source love child of iTunes and Firefox.
  • Climate change accelerating evolution – sounds fishy, but apart from some clever accounting, the Smithsonian guys aren’t exactly the lowest-regarded scientists on the globe.
  • Worst lyrics of all time – turns out that I had always mentally shuffled War Pigs lyrics to a more sensible direction, this tautology is terrible…
  • A very upmarket moleskine jacket. I’m happy with mine as-is, though the spine does exhibit worrisome tendency to age less than optimally.
  • Launch cost back in the boom: 5M$ and up,
    launch cost now: 12K and change. Things have changed. For the better, obviously.
  • Social networking and the chasm.
May 122007
 

San Diego MallThe third day opened with some of the most technical presentations amongst the offerings.

Virtualization Food Fight compared the various implementations, and refrained from making too bold predictions about the future. Sessions on realtime and performance optimization were interesting enough to prevent me from nodding off, same cannot be said of the lone post-lunch presentation. Seemed that quite a bit of the audience was lulled to sleep before being cut loose.

As the conference hotel was outside the town proper, there was an appropriately large bit of sightseeing and shopping to be done. Not to mention a dinner to take care of.

Confined shopping to a bare minimum, just a t-shirt and a book on the city.

A shaded corridor in Balboa ParkWalked around the Balboa Park for an hour or two – pretty much every attraction had closed at five already. But the park itself was interesting enough to hold interest. And the sunset over the trees and seriously spanish-styled buildings wasn’t shabby either.

Had dinner in Old Town San Diego – a part of the town that positively outclassed Tijuana in all respects. Shops looked like they stocked decent goods, and weren’t optimized to rip off visiting gringos in a horrible fashion. Food at restaurant named Fandango was very good – though my order, a shrimp-filled tortilla probably did not stretch the chef’s skills too much.

Sunset through the leaves of a palmtree Cacti and succulents

A maximally kitchy lamppost in Seaport Village A fortune teller in Balboa Park

May 102007
 

Collected the obligatory conference loot, and marched into the sessions.

The booty was on the meager side – though the sailor’s bag is nice.

Poster for my presentationThe sessions were a mixed bag. As if the conference organizers couldn’t get to grips whether this is a technical or marketing gathering. Right now it falls somewhere inbetween. Without much pain, fortunately, as there are between five and seven concurrent tracks, so there’s something for every attendee.

My own presentation went well. Despite a very thin crowd (below 20 in a 1400 attendee conference is downright disappointing) the session was very interactive, and plenty of questions were shot off by the audience. Most of which got a decent answer. The presentation will appear on Red Hat’s website at some opportune moment, stay tuned.

Jan 312007
 

Been a while since I stumbled onto the blog of Greg Kroah-Hartmann, one of the key Linux kernel hackers.

And there’s quite a crop of interesting things in the recent entries:

The most recent topic is the offer to assist vendors in crafting device drivers. While this effort is unlikely to budge the likes of ATI and Nvidia from providing binary drivers, it’s a mighty public relations blow for the kernel community – no longer can they be accused of being aloof and distanced.

Another interesting entry is the one on Linux Kernel in a Nutshell, a brand new book from O’Reilly. It’s a thin book on a weighty subject. And like a few other of the publisher’s books on the Linux kernel, it’s freely available on the web.

Jan 042007
 

For those about to click.

Jason Kottke has listed the cream of the crop of his 2400 links remaindered last year. Most still as interesting as on the day of posting.

Dec 152006
 

Click. Click. Click.

Jul 262006
 

Missed this year’s annual Linux Symposium in Ottawa. Fallen far enough from technical responsibilities to be a suboptimal attendee.

The traditionally quite thick proceedings are available, and at 900+ pages quite a handful.

Coverage at newsforge is done on a daily basis and available right now: tuesday, wednesday, friday and saturday (pretty much just the keynote).

Most of Linux Weekly News‘ coverage is still under embargo for non-subscribers and will be freely available in a week.

This year’s keynote speaker was Greg Kroah-Hartman, and he has conveniently put up the slides on his blog. And quite a presentation it is. One which probably provoked lots of interaction with the audience. Fortunately it’s not just slides that are available, but also additional background information. And how could any keynote that gives props to the flying spaghetti monster be anything less than great?

Jul 202006
 

Things that have alerted the powerful cybernoid lately:

  • Stat City is the coolest Threadless design lately (and I sure haven’t bought many t-shirts lately).
  • Crash-only software is another interesting article at lwn.net. And I refuse to use work-credentials to read about the ongoing symposium right now.
  • CNN interviews the guy who creates the occasional day-specific logos for google.
  • Prestige definitely shoots to the top of “should definitely see”-list. Christopher Nolan (with no bad movies on his belt) directing Hugh Jackman, Christian Bale and Scarlett Johansson on an interesting premise sure sounds worthwhile.
  • Pitwall, a Formula-1 management game. For the inner Jean Todts and Flavio Briatores. It cannot be any more boring than the real thing has been, recently.
  • Despite being officially abandoned by Activision, the Vampire: the Masquerade – Bloodlines game keeps getting gamer-provided patches to enhance the original release in many unexpected ways.
Jul 142006
 

Or a mojito, if you’re so inclined.

Dec 102005
 

Been a long time since the last.

  • Top 10 bookstores of the world. Have visited two of the nine that are still open. City Lights in San Francisco multiple times.
  • Wikipedia proves its worth again: a list of films ordered on the count of rudest english swear word. The Devil’s Rejects comes out on top with an amazing 5.13 f*cks per minute…
  • Typographic Style Applied to the Web, continuing on Bringhurst’s classic book on the subject. Very much a work in progress, but interesting content thus far.
  • A great spoof of Jakob Nielsen. Repurposing his classic “Frames are bad, mmmkay”-column for the AJAX-era.
  • A selection of movie posters with colors rephrased appropriately. The Kubrick one is the best of the bunch, the others are kinda bland.
  • Despair has its 2006 collection of demotivators available. The idea has been neatly retargeted on Linux distributions – with the prejudices played out well (debian’s elitism is snubbed in the bud, and you just gotta love the term “metric assload”).
  • Cthulhu Plush Slippers.
  • Misused metaphors. Haven’t used a single one, but a couple have been close calls.
Aug 182005
 

As noted below, O’Reilly’s conferences are indeed cool. Too bad OSCON Europe in Amsterdam is really really expensive (or am I just being cheap at 825 euros).

Never played around much with Scalable Vector Graphics – the early SVG-enabled mozillas were not paragons of stability, and Adobe’s implementation didn’t fare much better. The technology seems to have come of age, and future looks interesting.

TheFeature seems to have gone bust during the summer. One of the heralds of the bubble, it survived surprisingly long. Archives are available. Never was a big fan, don’t intend to leap in and scrounge for treasure.

MMORPGs are obviously big these days. Never tried one, so am not dissing them outright. Their existence and continuously up-ramping user numbers mean that a lot of changes in the games industry are bound to happen.

Another conference with interesting proceedings is the Linux Audio Conference. The realtime stuff is understandable, the acoustic less so.

And speaking of conferences, I’m horribly behind my original plan of providing a decent travel report from OLS2005. One day (soon) the rest of the event will be covered, till then the entries will stay fallow.

Jul 242005
 

This year’s keynote was given by Dave Jones, Red Hat’s kernel maintainer. Concentrated very much on problems in current error regression principles (or actually lack thereof). There exist quite a few problems – fault maintenance is not very well taken care of, and escalation principles between distribution vendors and the mainline are not really clear to anybody. The keynote was indeed a very single-minded affair, and contrasting it with last year’s world-embracing alternative does it no good. But then, last year’s talk was given by Andrew Morton, and he certainly did not feel constrained to stay under a single topic. Not a bad keynote, not at all; and if it brings better analysis/debugging tools, it definitely served its purpose. And no presentation where there’s talk of monkeys having crashed the speaker’s space ship can really be thought to be boring (“I know the guy on the left will not be piloting mine”).

I think next year’s keynote will be given by Greg Kroah-Hartman, but the identity was never made explicitly clear.

No additional swag was dealt out post-keynote, which was too bad. Previously google and O’Reilly have seen fit to reward attendees with shirts and books, respectively – but that didn’t happen this time.

Retired to Keg Steakhouse for dinner. Had a truly magnificently tender chunk of medium-rare cow accompanied by a twice baked potato. Dessert choice was not as optimal, as the “chocolat mousse cake” turned out to be both very heavy and Gargantuan-sized, though very tasty. Had to stop around the halfway point and was duly disrespected by both colleagues and the waitress.

Time to chill out for a while and then check out the official symposium nachspiel at Black Thorn.

Jul 222005
 

Notes on presentations to be decyphered from hieroglyphics in notebook.

EDIT 23.8.2008: Seems that I never got around to the decyphering part. Sad, really. The notes are available in paper form.

Jul 212005
 

Nope, the pub evening wasn’t very good, I’m afraid. Loud, crowded, hot and filled with only a couple of familiar faces. So retired early and woke even earlier. Not a perfect start for a long day.

Divided the sessions among the four of us (there’s four concurrent tracks), and I got the short stick and had to sit in on some very desktop-y presentations.

Linux 2.6 Roadmap by Jonathan Corbet (Linux Weekly News).
Like last year, the conference kicks off with a presentation about what was decided in the preceding kernel summit. Slides of the presentation are available at the LWN site.

This time around there were less major bombshells (ie. the development model had not been thoroughly changed, once again).

Presentation was divided into two parts – a recap where the kernel is right now, and where it is expected to move in the near future (though calling it a real roadmap is an insult to the cartographers of the world).

All in all the new development model seems to be in pretty good shape, Andrew Morton maintains the development flavored branch (the -mm tree), and Linus maintains the stable branch. Not perfect by any means, patches can, of course, avoid the -mm branch altogether and there’s no formal bug tracking going on. The adoption of sucker trees (2.6.x.y – maintained by Greg Kroah-Hartmann and Chris Wright), where only bugfixes are rolled in has been beneficial as well, since it prevents the need for wild backporting.

Another big development model-related thing is the sudden move from bitkeeper to git. Git is not at “1.0″-quality yet, and known issues exist (diskspace is wasted). Competitors exist as well (mercurial rated to be the best of the bunch).

The roadmap-portion of the presentation went on the vague side immediately when inclusion of a feature was not feasible in the next upcoming release. But it was still a very useful talk, since a lot of interesting, previously strenuously resisted features are making it in, now. Some of them already in the just-around-the-corner next release.

First up, 2.6.13, expected in august: kdump, inotify, execute-in-place, voluntary pre-emption, selectable timer-frequency.

The roadmap was not fully devoted to technical issues, process-related things were discussed as well (as shown on slide 24).

Latency improvements, ie. the time required to respond to an event, is a huge and hard problem to resolve. Ingo Molnar’s patches for “deterministic scheduling response time, always” are invasive and very hard to sell to the community as a whole (there are many beneficaries, but unfortunately everyday desktop use is not in for a big haul – audio/video, data acquisition and all kinds of [pseudo]-realtime control are). So each and every aspect must be argued individually, some of the improvements have already been rolled in, to a positive reception.

A controversial change is the move from spinlocks to priority-inheriting mutexes, where processes unable to run sleep instead of constant spinning. This brings with it the possibility for even wider pre-emption of processes in the kernel as well prevention of core stalling between entirely unrelated processes due to contention.

Another long-discussed change proposal is the implementation of all interrupt handlers as kernel threads. This would mean that everything is scheduled in a similar fashion. However, the additional locking primitives needed are not trivially determinable.

An “interrupt pipe” is another implementation of an improved handler. Both ADEOS and RTAI use it as the default mechanism.

Virtualization is a big and popular topic. So popular that a full day’s track (friday) is devoted to the subject. Xen is by far the leader in this niche. But far from completion – issues in scalability domain (ie. not ready for SMP or PAE).

On filesystem front the score is pretty simple: Reiser4 will go in “when it’s ready” as will FUSE. Cluster filesystems have a long road, as there’s no 100% clear vision which parts can a) be shared between implementations (especially the distributed locking manager, if at all possible) and b) need to be in kernel. GFS and OCFS2 are the two clear leaders here.

Security and resource management are moving along on expected routes, SELinux and CKRM, respectively. The support for TPM has already been added for the former.

Timekeeping has been changed to be more dynamic – for the benefit of virtualization (especially), there’s a separate presentation devoted to the issue.

Memory management has also been a target for tweaks, some of them large indeed (the 4-level page tables).

All in all the conclusion is that the kernel remains very much a “work in progress”, but steps are being taken into many interesting directions.

Building Linux Software with Conary by Michael K. Johnson (Rpath).
The slides are not available, the company site appears to be undergoing major reconstruction.

The rpath-guys have implemented a RPM-replacement called conary. Which does away with one of the most menial task of software configuration management (maintenance of the spec-file of a package).
Definitely an interesting addition to the currently available solutions is the availability of “shadows”, basically copy-on-write branches, that allow for trivially easy inheritance.

Python (the language) is used as definition language for building “recipes”, which are further simplified by the availability of superclasses (with which pretty much eg. most KDE-apps can use the same scripting).

The technologies involved are still evolving, and especially large scale SCM issues (releases etc.) are still incomplete.

[ And yeah, it's indeed the same Michael Johnson, who wrote a lot of the early "getting started with Linux"-type guides. Partially responsible for what I do these days, for sure. ]

Had lunch in the Teriyaki-place at the food court of Rideau Centre. Simple, fast and good, not to mention way healthier than the usual BK/McD/whatever-fare. Helsinki ought to have one as well.

SNAP Computing and the X Window System by Jim Gettys (ex-HP, laid off during the summit).
Slides available at freedesktop.org. Good summary at lwn.

Very much centered on the idea that current computers do not really scale beyond single users. Single screen, single mouse etc. Approaching ubiquitous computing, where applications follow users and users do not have to lug around any hardware. Also, the management of the environment is way too expensive – currently up to 3/4 of the cost of any non-trivial installation goes into maintenance.

Quite academic and necessarily provocative. Bluetooth is supposedly “useless”, whereas Zigbee is seen as a potential solution to networking issues.

The big idea is to make the “plumbing” of the network (eg. discovery and authentication of services) as seamless as possible. X must go truly multi-user, and that requires lots of design and implementation, eg. ssh is not seen as an adequate connectivity tool, but could be leveraged as the underlying transport – it has legal issues (export control) and is not ever truly ad-hoc (needs an account on the target system). IPsec is not usable either – it is not end-to-end, and does not handle user-level authentication.

Input devices must become true network services, otherwise the plumbing’s only half-done – the control must be able to migrate between devices.

And services must be able to be seamlessly used, without regard to network topology. HAL and DBUS technologies are seen as big enablers in this area.

Clearly the problem domain is much wider than just graphics, and there are really no places to copy good ideas from – so it’s really time to innovate.

TWIN: An Even Smaller Window System for Even Smaller Devices by Keith Packard (HP).
Slides available at freedesktop.org.

Easily the best speaker thus far, and pretty much in the top 5 ever (among technical folks, that is). Keith Packard’s an old X Window System guru and it shows – the presentation is peppered with war stories and anecdots from old days.

The basic idea behind the presentation is the need for a new truly lightweight window system – lightweight in the sense of memory footprint, not in CPU consumption. And with severe wizardry (more than adequately explained in the material) the entire system including scalable fonts, translucency support and PostScript-based geometry engine fits in 100 kilobytes. Yes, one hundred kilobytes. That definitely qualifies as lightweight. There are a lot of interesting shortcuts taken, while hugging the requirement set at height of several molecules only – showing that truly impressive results can be had even when the initial set of reqs seem mindbogglingly hard.

Can You handle the Pressure? Making Linux bulletproof under load by Martin Bligh (IBM).
No presentation available as far as I googled.

Struggling to make the virtual memory system of Linux truly bulletproof is a painful task.

The presentation described the current state of affairs and included ideas how to improve the situation.

The current state is that the behavior is easily explained, but contains lots of issues. Basically all memory is used – and some of it is easily reclaimable when needed. Clean pages can be reclaimed immediately, whereas dirty ones must be dumped onto backing store first. The current page selection algorithm is LRU (with lots of extra spicing on top), based on HW-level information (pages). Complicated by the need to balance pagecache and slabcache (kernel’s pages) with the users’ paging needs.

By far the most problematic structure at the moment is the buffer-head, which has a lot of dependencies and is thus extremely hard to reclaim (eg. filesystem metadata caching, differences between filesystem blocksize and HW page size, mappings between data in memory and on actual disk surface, ordering guarantees for transaction-based entities).

Some pages are just plain unreclaimable – eg. kernel, locked pages, RDMA. But a big omission in the current system is the lack of differentation between physical and virtual pinning of pages, they are after all two separate address spaces and should be treated as such. Fragmentation of memory complicates reclamation further (especially when most kernel structures are definitely sub-page sized). Dependencies are not managed well – a full tree to map eg. inodes/dentries/pagecache entries is needed.

The OOM killer is usually a good first sign that there’s either a) suboptimal workload b) bugs. Usually the former. But the diagnostics provided by the killer are not as good as they could be. Usually there’s just indication how much memory is not available, and that’s not enough in most cases.

Clearly there’s a need for better tools here. Both to monitor the memory consumption (both live system [ie. instrumentation] and in postmortem fashion), current state of the art vmtop and meminfo/slabinfo do not reach very far. Some ideas to create “event receptors” with priority sockets exist, but no complete implementation is available. Recreation of the fault is usually between hard and impossible, and kprobes/tap cannot be hooked in after the fault has manifested itself. The dirty page evaluator is slow, and usually not available – heuristics to switch between two modes at certain threshold would be beneficial.

Instrumentation would indeed be very good addition, but both space and performance criteria apply – adding per-page tags is not easily accomplishable.

In swapless systems the code short-circuits and avoids very lengthy page management methods.

This time it seems that no free sodas are offered, only water.

Ate dinner in Fishmarket restaurant, monkfish is still a good selection.

Visited the Intel/IBM-hosted evening reception in the conference center. And quite something else it was. The initial presenter from Intel was slick and harmless (especially considering how much longer he could have spoken). Performance was marred by the revelation that he was actually showing slides from an XP-machine (to loud booing). Which was probably a wise choice, since the next presenter took a sweet fifteen minutes to tune his X-window system settings before commencing the show. The less said about the quality of the content, the better. The evening was capped off by a traditional lottery, but someone had obviosuly screwed up gravely, since among the twenty-odd tickets drawn were no winning matches whatsoever. So, the speaker switched over to trivia questions, to which the answers shouted to – kinda putting anyone sitting more than five meters distant at a severe disadvantage. Drinks were available, otherwise I (and I guess most of the others as well) would’ve left before the official program had reached its halfway mark.

Jul 192005
 

Registered to the conference. Good loot – not one, but two t-shirts (the other provided by the newly minted Intel Open Source Labs). Bought a hardcopy of the proceedings as well. By-invitation annual kernel summit and the very first desktop developers’ conference were ongoing, took a peek into the latter (based on a six second analysis, the guys were discussing the future of KDevelop).

The adjoining Rideau Centre mall is its old trusty self. Food court with variety and a smallish selection of interesting shops. HMV’s sales are as good as ever. EB’s PC game selection has gone down some 80% from last year’s. Radio Shacks have mutated into something called “the Source”.