Advogato blog for mjg59

The fallacy of the completely inclusive community

Mon, 21 Jul 2008 13:06:56 GMT

Emma Jane Hogbin gave a presentation on the gender gap in free software at Lugradio Live this weekend. One of the central messages was that a great deal of how to avoid putting women off computing can be distilled down to "Don't be a dick". This ties in well with Mako's restatement of the Ubuntu code of conduct as "Be excellent to each other" (a wonderful phrasing which demonstrates that Bill and Ted's Excellent Adventure is the most philosophically worthwhile film that Keanu Reeves has ever appeared in, and certainly not The fucking Matrix) and led to my 5 minute rant on why I hate the Linux community slightly later in the day, but does leave a certain problem. What standards are used to define whether given behaviour is dickish or not? The comments here show that there's disagreement even within a single sub-community of the larger free software world. Ben suggests that the reaction to perceived inappropriate behaviour is perhaps even more discouraging than the original behaviour, suggesting that bitching about things that offend you is dickish behaviour in and of itself. How do we decide whether someone is being a dick or helping the community? Is lack of tolerance a form of exclusionary behaviour?

This topic is actually one of the issues discussed in the Geek Social Fallacies, but here's a nice easy example. Would tolerating planet posts encouraging the eradication of the Jewish population be inclusive or exclusive? I suspect that most people would agree that it wouldn't be acceptable behaviour, which leads us to the next question. Why? There's two obvious arguments here. The first is that at a community level we have some form of rough moral consensus that advocating genocide is Just Wrong, and so criticising Nazis is obviously the right thing to do. The second argument is more pragmatic than philosophical - alienating millions of people in order to avoid alienating hate groups could be considered to reduce our potential contributor base in an unfortunate way.

I'm a fan of the second argument. The example I gave is emotive and relatively recent history has resulted in people tending to be pretty uniform in considering genocide to be a bad thing, but many other cases aren't clear cut. What I consider to be objectification of women is seen by others as appreciation of natural beauty. What I think of as sexist jokes are perceived by others as acceptable humour. When I advocate intolerance of certain behaviour, people are going to see me not having enough tolerance. So we end up in a situation where people make the "We should all just get along and be tolerant of each other" argument, which sounds fine but is fundamentally flawed in one significant way.

Advocating tolerance excludes the intolerant.

The reason people fail to see this is that it doesn't sound like a flaw. If you ask people whether we need to support intolerance, the immediate answer is probably no. But by advocating exclusion of intolerance, you're excluding all those who have good reasons to be intolerant. You're excluding the women who don't want to feel that the community sees them as a pair of breasts attached to some legs. You're excluding the ethnic groups who would prefer to avoid racist slurs or ethnic stereotyping. Telling anti-fascism protestors that they're being intolerant isn't likely to endear you to them. Advocating tolerance is telling the intolerant that they're wrong and should just deal with whatever it is that makes them unhappy.

So, ironically, tolerating certain types of intolerance is probably required in order to avoid alienating many potential contributors. That means some way of deciding what kinds of behaviour are acceptable and which are unacceptable. In the absence of either pre-existing community consensus or some philosophical breakthrough that allows unambiguous determination of the "rightness" of a given action, I'm going to suggest that we look at it from a pragmatic viewpoint. How many potential contributors do we discourage by criticising a certain type of behaviour? How many do we discourage by tolerating it?

The fallacy of the completely inclusive community is the idea that it includes everyone. The reality is that a certain level of social exclusion is required in order to include a wider range of people. So don't criticise people purely for criticising someone else's behaviour - make an argument for why that behaviour benefits the community. And when you see behaviour that you think discourages others, call people on it. Even if nobody's behaviour changes as a result, you're sending a signal that not everyone in the community agrees. Sometimes all people want is to know that there'll be some people on their side.

But, above all, try not to be a dick.

15 Jul 2008

Tue, 15 Jul 2008 02:05:22 GMT

Plans for the month:

18th-20th: Wolverhampton for Lugradio Live where I'll be doing some sort of presentation on some sort of power management stuff.
22nd-27th: Portland for OSCON and the Oregon Brewers Festival (which I guess settles any arguments about how to spell plumbers)
28th-30th: San Francisco for a meeting that's been moved to the week before I'm there
31st-4th: Boston in order to meet some of the people that I actually work with

Things not planned for the month:

Genocide
Puritanism
upskirt photos
Telling women who fail to cover their legs that they're asking for it

My trip to Istanbul by Matthew Garrett aged 28 and 4/365ths

Mon, 14 Jul 2008 00:05:56 GMT

Saturday

Arrive at Heathrow. Richard gets to be my special lounge buddy - we later discover Bastien sitting outside looking like a lost puppy. Flight is delayed by a mere hour, so we get to the hotel with little trouble and check in. Dinner with Luis and co on pillows on the street. This becomes a recurring theme. Drinking is involved. This also becomes a recurring theme. People complain about my shortcut finding skills.

Sunday

See beautiful things. Thankful to finally get to see buildings older than my old college. Dinner under some bridge with Red Hat folks where we discover the joys of the "special price". People once more complain about my shortcut finding skills. Suspect pillows are involved, but hazy recollections.

Monday

Arrive at the university by taxi. More to the point, arrive at the university by taxi without taking a 30km detour. Dinner with Canonical people, then a party in some overpriced bar on the top of a very big hill. Discover that taxi drivers in Istanbul either have no fucking clue where anything in the entire world is, or that driving tourists to bizarre locations is a national pastime. Avoid this fate and arrive home at something like 4AM.

Tuesday

Corporate whoring continues with dinner with Collabora people (delayed by two and a half hours because Christian values getting sweaty with other men over eating, or something), followed by more drinks on the pillows. Am vindicated when it turns out that my route back to the hotel would in fact be the shortest possible route back if people didn't keep insisting on making random left turns when we're almost there.

Wednesday

Fascinating (and increasingly drunken) discussion of the neurobiological aspects of colour spaces with Pippin precedes drinks on the roof of the university. Narrowly prevent Luis' attempt to leave the foundation open to flagrant copyright violation suits. More pillows.

Thursday

Wake up with a twisted ankle and a broken laptop. I had a good birthday, it seems. Collabora host a party on a boat. Miraculously, nobody falls off the boat. We head back to the pillows while others trudge up the hill to Taksim. Aaron wins the inaugural Aaron Bockover award for services to the GNOME community.

Friday

Dinner with Novell, demonstrating my even-handedness when it comes to accepting corporate favours. Miguel reveals his true nature as a Microsoft shill by admitting to owning an XBox. I advise him to raise his free software credentials by getting a Freerunner - as a bonus it'll crash whenever anyone tries to call him, preventing Microsoft from whispering more sweet nothings in his ear. A foolproof plan. Party paid for by Google. Ear bleedingly loud. Some drinking involved. Return to bizarro deviant pillows where we are treated to the spectacle of child labour. Spend some time wondering why Planet Fedora is discussing upskirt photos and decide that hating the entire human race is probably the best option.

Saturday

Turns out that while the Grand Bazaar is effectively just a shopping centre, it's a fucking giant shopping centre that sells nothing I can find any excuse to want. Wander over to Asia for dinner. Conversation with Lennart about using cgroups as a mechanism for providing application latency requirements and how the current lack of standardisation of mountpoints and exposure of irritating implementation details makes it almost impossible to use them for anything. Fascinating diversion into how to deal with getting a SIGBUS when your mmap()ed soundcard gets hotswapped, including deciding that the easiest way of getting a reliable indication of your current process maps is by, erm, parsing /proc/self/maps. Final pillows trip. Emotional farewells (by which I mean more drinking)

Sunday

Airport. Plane. Train. Home. Transfer hard drive into laptop with working screen. Discover that productivity not actually enhanced by having more than a 300x200 pixel area of functionality. Decide to write libelous article about previous week instead.

30 Jun 2008

Mon, 30 Jun 2008 12:18:42 GMT

On a tastelessness scale of 1 to my fstab looks like rape, this scores a 17.

30 Jun 2008

Mon, 30 Jun 2008 11:12:07 GMT

If airlines were like software, then nobody would ever fly because they'd be put off by the fact that everyone who did ended up as a small pile of charcoal.

CAN HAS WORKING INTERWUB AND WEB BROWSER AND PACKAGING SYSTEM?

NOT FOR ME :(

Hello people with Sony laptops

Wed, 25 Jun 2008 18:07:08 GMT

Could you lovely people with Sonys do a quick test for me? Download this file and stick it in /usr/share/hal/fdi/information/10freedesktop/ and restart hal. Make sure that you have the sony-laptop module loaded beforehand and let me know if your hotkeys don't do what's written on them. If they don't work at all, don't worry for now - there are various Sonys that are still broken and this won't fix them. I'm just interested to know whether the mapping used is correct.

Power management design philosphy

Tue, 24 Jun 2008 16:09:54 GMT

One of the traditional problems with power management has been balancing power savings against reduced functionality. The two traditional approaches to this have been to have sane defaults or to let the user tweak them, with a hybrid approach being to have sane defaults and an "advanced" box that lets users set their own parameters.

Both of these options suck.

The problem with sane defaults is that power management is an area where the "sane default" genuinely does differ between users. Usage patterns will determine the appropriate spindown period for a hard drive. AHCI's ALPM will disable hotswap detection, which is fine for home users but a pain if people want to rip out a failed RAID element. ALPM also introduces a small amount of latency (on the order of a seek in the most aggressive mode), which is entirely irrelevant for almost everyone but is a pain if you're trying to offer i/o latency guarantees. PCI-E link power management adds small quantities of latency. Letting the CPU run to full speed whenever it wants to is good for power management but potentially bad for thermal management. Screensaver timeouts vary depending on whether you're watching a movie or not.

The problem with leaving everything tweakable is that you're asking users to make choices about things but not giving them the information they need to make those choices. Whether you get a power saving from hard drive spindown depends on whether the drive is idle for long enough to save the power you'll spend spinning it back up. Get it wrong and you'll be putting your drive under extra load, reducing performance and consuming more power than you were to begin with. If you limit the maximum speed of your CPU to keep it cool, you'll be wasting power and performance even when it's well below the thermal limits. Disabling ALPM because you might want to change a RAID device at some stage means you're consuming power despite generally not needing to use the additional functionality.

But while these options both suck in different ways, they share one fundamental failure. They both imply static configuration. The correct power management policy depends on the way that a machine is being used at a specific instant in time, and no matter how many power management profiles you add there's no way for a user to switch between them fast enough to obtain a decent power/performance ratio.

Adaptive power management adopts a different strategy. Rather than define a static policy (or several static policies), the hardware is monitored to determine the best power management settings. An example of this is the ondemand CPUfreq governor. Rather than attempt to provide a static configuration, the processor frequency is automatically changed to meet demand while also keeping the overall power consumption as low as possible. This patch adds a thermal component to its policy, preventing the machine from overheating. Result? No requirement to provide tunables to userspace.

Something similar is achievable with hard-drive spindown. By simply monitoring how often reads or writes actually hit disk, it's possible to automatically adjust the spindown period to obtain decent power savings while reducing the number of spinups. This approach is imperfect - in an ideal world we'd know to spin the drive up before it's needed, but that simply isn't possible. However, the user is almost certainly unable to make a better guess. It's not realistic for a user to be able to predict whether or not a given page is still in cache or has been evicted. Nothing is lost by providing a dynamic policy, and another unnecessary tunable has vanished.

The difficult part of an adaptive policy comes when roles are switched in ways that don't correspond to changse in hardware status. One of the most common cases is that of screensaver settings when the user is watching a video. It's not practical for the kernel or a system daemon to predict this case, so we have two choices:

Get the user to switch to a "media" power policy and then remember to switch back afterwards
Have the media player deactivate the screensaver at startup and reactivate it when the video isn't playing

.One of these choices involves the user having to explicitly state something that's obvious - playing a video automatically implies the desire to adopt a different power management policy, and so asking the user to manually adjust that is ridiculous.

The loss of hotswap notifications when ALPM is enabled? Simply reenable it if SMART starts complaining or the RAID set becomes degraded or a filesystem is unmounted or any of the other things that will have to be done before a drive can be safely removed. Latency an issue? Let userspace tell you what its latency requirements are. When we get down to it, the only settings that we can't infer are things like idle-time-to-suspend, screensaver settings and default brightnesses. Which, curiously, are about the only things that Mac OS exposes[1].

The problem we face is that we don't currently have interfaces to let applications tell us what their requirements are. This is theoretically straightforward, but getting it right is important. Beyond latency and screensaver issues, what constraints do applications want to impose? How can we expose an interface to those constraints? This is the sort of thing we'll be looking at at the Linux Plumbers Conference, so if you have ideas about what they'd need to look like then sign up. Or, even better, submit a paper and be part of the process that gets Linux's power consumption as close to the theoretical minimum as possible.

[1] My Vista system gives me 25 options which can be set for each of AC and battery.

Intel power saving

Tue, 24 Jun 2008 13:08:42 GMT

It's sometimes surprising where power goes in a laptop. One of the things busily consuming power is the digital link between the graphics hardware and the TFT, which is busily updating your screen 50 or 60 times a second. That's kind of unfortunate, because most of the time nothing's actually changed. Unlike CRTs, TFTs don't have the same requirement for rapid updates to maintain an image - reducing the vertical refresh rate (within reason) won't result in any reduction in image quality. What it will do is result in jerky movement and blurring, though, so doing this by default is a problem.

The obvious way to handle this would be to downclock the display when it's idle and upclock it again when it's active. Doing so gives the benefit of reduced power consumption when not much is going on (most of the time) and not impairing image quality. Programming clocks takes a noticable amount of time, and doing it while they're controlling the display results in nasty screen flicker. Thankfully, Intel hardware has two sets of clocks per output. One can be programmed at high frequency, and the other at low frequency. On pre-965 chipsets, we can then simply flick between them whenever the screen becomes idle or active - the clocks are already set up and the hardware waits for the next vblank before actually performing the switch, so there's no blurring or flicker. 965 theoretically does all of this in hardware, but I haven't actually tested that yet. In principle the patch sets it up, but...

The savings seem to be on the order of 0.5W or so, though that'll probably depend on your screen resolution. Patch against current git is here, and a precompiled version of the driver for 32-bit is here. The most likely problem is screen flicker when idle, so if anyone sees that then let me know and we'll see if it can be tuned.

20 Jun 2008

Fri, 20 Jun 2008 02:06:13 GMT

Some months after I got the MPAA's University Toolkit taken down for violating my copyright, the websites have degraded to the point of giving "bad request (invalid hostname)". Which leaves me curious - did the MPAA drop the entire program, or is it all just done with significantly less publicity now?

18 Jun 2008

Wed, 18 Jun 2008 23:07:09 GMT

The Linux Plumbers Conference[1] now has a call for papers, with registration also being open. Why is this important? Because it's the first conference aimed at getting together developers from all walks of the Linux world and fixing the core infrastructural problems. Ever looked at a kernel interface and wondered how the christ any userspace programmer was supposed to use it? Ever looked at a desktop application and wondered what kind of $2 crack they were on when they wrote it? Here's your chance to find out or get it fixed.

I'm running the power management microconf. We're looking at discussing what sort of interfaces the kernel needs to export to userspace and how userspace needs to make use of them. Want to be part of engineering the first OS to have high quality power management all the way from embedded to servers? Be in Portland in September. Ideally at the conference rather than a bar, though there'll be plenty of time for that as well.

So, if you have opinions on power management (or any of the other topics), sign up now. Otherwise we'll ignore them and you'll be unhappy.

[1] Plumbers? Plumbers'? Plumbers's? Almost certainly not Plumber's.