I asked a bunch of hard architecture questions, now for a softball Q. Your favorite hack WRT kernel internals and kernel programming in general. drivers, innards, I don't care which. The kind of thing where you took a look at the code and go 'holy cow thats cool' or whatever. You define favorite, hack, and kernel. Just wanting to kick back and hear a story about cool code.
To define my question, people would think it weird or bizarre to have a kernel that does NOT have ext3 or ipv4 compiled in or at least available as modules. Pretty much everyone expects to see a linux kernel with loop, or sg available. When or if or should people expect to see realtime extensions compiled in by default on pretty much any linux box? As a guy running CNC machines for a LONG time under linux using emc, I've always figured the sound, or video guys would demand realtime "soon" making life a little easier for me, but it never happens.
As the IT wheel endlessly rotates and noobs think they're the first to invent old ideas like tokenization or virtualization or storing stuff on the network, what is your favorite IT trend/fad that's NOT currently popular that you're looking forward to its inevitable rotation back into the limelight...
If you had to do GIT over again, what, if anything, would you change? VERY closely related question, do you like the git-flow project and would you think about pulling that into mainline or not?
A lot of classical fantasy had a dearth of women as characters
With childhood death rates around 80% any culture that doesn't do the barefoot pregnant and in the kitchen thing is literally going to disappear in at most a couple generations. As the Bechdel wiki page contains "A work may fail the test for reasons unrelated to gender bias, such as because its setting works against the inclusion of women"
It's like expecting sci-fi to explore what it's like to be a single person living in New York city: it's kind of missing the point.
Good, hard sci fi, you mean.
Bad soft sci fi like "stranger in a strange land" which is a very thinly disguised veneer of sci fi pasted over a 60s california hippy commune story, which doesn't appeal to me so I found it to be truly awful sci fi.
Yeah, you're sorry. Now the poor admin and his friends need to walk and walk and walk, now not including Tom Bombadil, and walk and walk all the way to the data center, which now closely resembles a volcano due to the/. effect, to reboot the server, because no one can explain why the eagles can't just fly there and take care of it, because (insert a whole bunch of mumbo jumbo).
Combined with redefinition. Unemployment is low and dropping because labor force participation rate is dropping even faster. Eventually none of us will have jobs, but as we stand in the soup lines we'll see unemployment has dropped to merely 5% and good times are right around the corner.
So we'll simply redefine such that the only "automobiles" on the road subject to the 60 mpg limit will be smart cars and Fiat Puntos (a real car, I rented and drove one in Ireland, and it was a fun and surprisingly comfortable little car). Tahoes Expeditions Escalades and the like will be redefined to be 4-wheeled motorcycles thus exempt from the 60 mpg regulation.
cars in the US are stupidly large for no good reason.
Compensation for certain body part being smaller. Its pretty deeply ingrained culturally. This being/. no body knows but I had a female friend who swore that was true, I guess she saw enough to make a pretty good graph. I'm frankly embarrassed to be seen renting the giant home depot pickup truck, thinking that the ladies are looking at me and feeling sad for me because I must be so small I'm an "innie", you know like when its -20 F outside.. shrinkage.
What do Detroit, or Stuttgart, or Tokyo have waiting in the wings that will get to the Obama administration's target of 54.5 miles per gallon (mpg) by 2025?
Campaign contributions to get that bad boy dropped to about 8 MPG.
Followed by Sierra Club campaign contributions to raise it to 700000 MPG.
Followed by auto industry contributions to drop it back to 8 MPG
You get the idea. Very profitable, for campaign advertising directors, the legacy media platforms who get most of the ad budget, etc. For everyone else, we get screwed but thats business as usual.
There's no turbine or continuous generation of power and the design of it pretty much seems to preclude such use.
The walls heat up. That energy is going somewhere. Tell your local thermodynamics engineer, "You dump 10 MW of electricity into it, and magically the walls get 200 MW of heat at a million degrees or so, now do your Rankine/Carnot thing and generate 100 MW of electricity". Stand back and let the engineer work, and ta da !
Unless the engine is designed to disintegrate upon shutdown, it didnt shut down.
Not mutually exclusive. Historically most engine failures happen somewhere between 0% and 100% power VERY rarely when at full power.
Right off the top of my head, spending too much time around critical shaft speed, flow separation from one side of the nozzle and not the other collapses it (some are tough enough to resist, some not), hard starts (well, stops) where ignition stops for an instant and fuel oxy accumulate in the chamber and suddenly ignites all at once poof kaboom... Or screaming combustion instabilities as the pressure drop across the injectors drops... Another classic is a bearing is going on the turbopumps so efficiency drops by 1% at full power but the engine keeps going until you shut off the power, then the turbo spins down and instantly seizes going from 50K rpm to zero in a fraction of a rotation... well, the axle stops, but the blades usually fly off when that happens. Oh and obviously leaky shutoff valves... You engineer those guys to not shut off accidentally, if they leak a little thats better than an uncontrolled accidental shutdown, so leak in the chamber, spark off a hot spot and kaboom. I don't know their plumbing but if they did the old "one set of valves to start, one set to stop" obviously a partial shutoff valve failure could flow broken valve parts into a full speed rotating turbopump. I'd give 50:50 odds I listed the failure mode above. Who knows if they'll recover enough parts in good enough condition to figure out the root cause.
The Space Shuttle carried 28,000lbs to the International Space Station for about $400 million per launch.
LOL you wish it was that cheap. You took total contract cost divided by number of missions for spaceX, why not for space shuttle? Because the numbers don't match your axe to grind. Here I'll do the data gathering and division for you:
From wikipedia "The actual total cost of the shuttle program through 2011, adjusted for inflation, is $196 billion." (this is pure BS, to "do it all over again" would easily cost over 300B, but I'll use the artificially low PR/marketing BS number for the sake of this argument) divided by 135 missions (unsure how to account for disasters) yields 1.452 billion dollars per 28K lb mission absolute minimum, real world is going to be much more.
So you're looking at 1.6B vs 1.5B, not much of a difference given "nasa accounting" thats a rounding error.
There are serious issues why the shuttle program had to end which began in the 80s, so its pointless to debate what if we continued it. For example we lost about 1 shuttle per 50 flights, and the production lines shut down permanently in the 80s. So if we launch until they're all destroyed, we soon would have no launch capability at all, and merely have to farm out to spaceX later, and the only thing waiting does is make stuff more expensive. I suppose we could R+D and reopen the production lines to build more 1970 era space shuttle orbiters, but that will absolutely explode program cost above the "cheap" 1.5B per launch. Or we could R+D even more and build new 2010 era space shuttle orbiters, that would probably be overall a bit cheaper but still boost program cost above 1.5B.
If you wanted to continue the shuttle program, that decision had to be made in the 80s when the last orbiter rolled off the assembly line and the clock started ticking on the program shutdown. Sunday Oct 07 2012 is a bit late to the party to decide the orbiter production line should have been kept open back in April of 1985. First, build a time machine and go back more than a quarter century...
Well that was embarrassing. That would be Parallax Inc, before the prop came out mid last decade (its old) they were famous for the basic stamp which I guess you'd call the Ardweeeeeeeno of 1990.
Microchip makes the PICs. I was thinking of something along the lines of instead of buying 8 cores of 80 mhz 2005 era propeller for $8, buy 8 PIC24's in 20 pin DIP packages (easy for noobs to prototype) for a bit over a buck a piece and tie the I/O lines together and learn the agonies of multi-processor interfacing...
Comparing it to Pi is a little disingenuous. Reading the copy suggests there is an ARM core, plus some number of co-processors (perhaps like the Cell and its SPEs). That would make it a non-general-purpose processor. To compare apple-to-apples, we'd have to know how it compare to modern GPUs.
As for apples to apples, It's vaporware specs read similar to the old printout of the vaporware specs for the Propeller2 from microchip inc on my desk.
They are nearly identical situations, in fact, both small teams (the original prop was done by one guy, admitedly 6-7 years ago). Gigaflops/sec performance goals, etc.
As for which is the better vaporware product I think you're slightly better off with the parallella story than the prop2 story, but slow working silicon purchased online by CC and delivered by UPS next week always beats fast vapor, so whoever gets there first, wins....
To make parallel computing ubiquitous, developers need access to a platform that is affordable, open, and easy to use.
They promise the latter three, but "access" seems a bit lacking. Also they specifically left out performance but talk it up in separate marketing materials (5 watts for 45 GFLOPs etc)
Some other alternatives optimizing for local maxima in the solution set:
Just simulate in software, if you don't care about speed but want to learn to program parallel. Erlang? They seem to have a fixation on C, why not use the right tool?
Go to opencores.org and stick a zillion cores on a off the shelf FPGA dev board. Or a fat stack of picoblaze or microblaze if you're willing to deal with the annoying licensing hassles (my advice, stick with opencores to avoid legal hassles, the weird licensing for the *blaze family is like the creepy dude in a van offering kids "free" candy)
They seem spread a bit thin based on clicking around the website. They're doing everything but invent hard AI and the warp drive on their website, which is a lot for just 4 people. Their kickstarter seems pretty firmly grounded in comparison.
One of those "infinite spare time" play toys would be to stick a bunch of 6809 cores (or pdp-8s or -11s or Z80s or whatever) on one of my FPGA boards and figure out the glue logic. Anyone with a big enough board could download by VHDL/Verilog and go for it on their own hardware.
I suspect its going to be an action and special effects demo reel with as thin a layer of plot "frosting" as possible. Like the latest star trek movie.
Its kind of like hoping for a Ringo / Aldenata / Posleen movie.. it would just be a sci fi horror gore-fest shoot em up, pretty boring compared to the books.
Why isn't it educational?... without having learned....
Modern education means you'll pay some at least semi-crooked corporation as much money as they figure they can get you to borrow, in exchange for a sheet of paper you can show to someone who knows nothing about anything other than that a piece of paper qualifies you to have a job. Currently it ranks right up there with "I watched an old episode of NOVA on PBS" and "I have a certificate/associates degree" hard to say which of three three prioritizes lower.
I know it doesn't have much to do with the "real" or "old" definition of education or training, but it does reflect modern reality.
complaining how everything sucks
Fair enough. Four things work: 1) Smart enough to know how to learn, plus internet access = self education. Don't really need much else anymore. Not access to subscription contracted flash websites that happen to be on the internet, not filtered internet, just raw search engine and internet. 2) Printing press seems helpful especially for workbooks (I was just kidding about the whine about papyrus being invented) 3) Improved student:teacher ratio always seems to help 4) Getting the students interested in the topic via social pressure or whatever works to light a spark
"California CEO Meg Whitman told financial analysts today that it will take until 2016 to turn the state around. Surprisingly, Whitman put some of the blame for the state's woes on its IT systems, which she said have hurt its internal operations. To fix its IT problems, Whitman said the state offices are adopting Salesforce and HR system Workday. The state also plans to cut benefits and entitlements. It said it has 2,100 different forms alone; it wants to reduce that by half. 'In every state we're going to benefit from focusing on a smaller number of entitlements that we can invest in and really make matter,' said Whitman."
10 middlemen retailers all with a policy "we will pricematch any competitors price for the identical model". Well, if walmart is the only retailer on the planet who sells model 13513.2362 then I guess they'll never have to pricematch, will they?
Also add some B+W only models, some multifunction models...
... if they were using/. UID numbers and./ Karma and the/. friend/foe network and all that, I bet the results would be far more informative.
I think/. should allow klout linking... I think it would really further my career to be known as highly influential WRT goatse, TRS-80s, and being grouchy.
Gotta wonder what they are flying now. Keep in mind that these huge telescopes are not pointed at the cosmos.
Aside from the political stuff I have a serious scientific question, one end of a scope is the room temp end pointed at the (on average) room temp earth all the time, and the other end of a scope alternates between hot sunlight and frozen deep space every orbit. From a technical perspective, are there modifications to the thermal system required, and if so are they the "expense" they're complaining about? If it's cheaper technologically to continue to point "down" I would imagine there's some interesting earth science they could do.
Slashdot Mirror
You ever get rickrolled or goatse'd or trolled on /. historically?
I asked a bunch of hard architecture questions, now for a softball Q. Your favorite hack WRT kernel internals and kernel programming in general. drivers, innards, I don't care which. The kind of thing where you took a look at the code and go 'holy cow thats cool' or whatever. You define favorite, hack, and kernel. Just wanting to kick back and hear a story about cool code.
To define my question, people would think it weird or bizarre to have a kernel that does NOT have ext3 or ipv4 compiled in or at least available as modules. Pretty much everyone expects to see a linux kernel with loop, or sg available. When or if or should people expect to see realtime extensions compiled in by default on pretty much any linux box? As a guy running CNC machines for a LONG time under linux using emc, I've always figured the sound, or video guys would demand realtime "soon" making life a little easier for me, but it never happens.
As the IT wheel endlessly rotates and noobs think they're the first to invent old ideas like tokenization or virtualization or storing stuff on the network, what is your favorite IT trend/fad that's NOT currently popular that you're looking forward to its inevitable rotation back into the limelight...
If you had to do GIT over again, what, if anything, would you change?
VERY closely related question, do you like the git-flow project and would you think about pulling that into mainline or not?
A lot of classical fantasy had a dearth of women as characters
With childhood death rates around 80% any culture that doesn't do the barefoot pregnant and in the kitchen thing is literally going to disappear in at most a couple generations. As the Bechdel wiki page contains "A work may fail the test for reasons unrelated to gender bias, such as because its setting works against the inclusion of women"
It's like expecting sci-fi to explore what it's like to be a single person living in New York city: it's kind of missing the point.
Good, hard sci fi, you mean.
Bad soft sci fi like "stranger in a strange land" which is a very thinly disguised veneer of sci fi pasted over a 60s california hippy commune story, which doesn't appeal to me so I found it to be truly awful sci fi.
we'er sorry
Yeah, you're sorry. Now the poor admin and his friends need to walk and walk and walk, now not including Tom Bombadil, and walk and walk all the way to the data center, which now closely resembles a volcano due to the /. effect, to reboot the server, because no one can explain why the eagles can't just fly there and take care of it, because (insert a whole bunch of mumbo jumbo).
Combined with redefinition. Unemployment is low and dropping because labor force participation rate is dropping even faster. Eventually none of us will have jobs, but as we stand in the soup lines we'll see unemployment has dropped to merely 5% and good times are right around the corner.
So we'll simply redefine such that the only "automobiles" on the road subject to the 60 mpg limit will be smart cars and Fiat Puntos (a real car, I rented and drove one in Ireland, and it was a fun and surprisingly comfortable little car). Tahoes Expeditions Escalades and the like will be redefined to be 4-wheeled motorcycles thus exempt from the 60 mpg regulation.
cars in the US are stupidly large for no good reason.
Compensation for certain body part being smaller. Its pretty deeply ingrained culturally. This being /. no body knows but I had a female friend who swore that was true, I guess she saw enough to make a pretty good graph. I'm frankly embarrassed to be seen renting the giant home depot pickup truck, thinking that the ladies are looking at me and feeling sad for me because I must be so small I'm an "innie", you know like when its -20 F outside .. shrinkage.
What do Detroit, or Stuttgart, or Tokyo have waiting in the wings that will get to the Obama administration's target of 54.5 miles per gallon (mpg) by 2025?
Campaign contributions to get that bad boy dropped to about 8 MPG.
Followed by Sierra Club campaign contributions to raise it to 700000 MPG.
Followed by auto industry contributions to drop it back to 8 MPG
You get the idea. Very profitable, for campaign advertising directors, the legacy media platforms who get most of the ad budget, etc. For everyone else, we get screwed but thats business as usual.
There's no turbine or continuous generation of power and the design of it pretty much seems to preclude such use.
The walls heat up. That energy is going somewhere. Tell your local thermodynamics engineer, "You dump 10 MW of electricity into it, and magically the walls get 200 MW of heat at a million degrees or so, now do your Rankine/Carnot thing and generate 100 MW of electricity". Stand back and let the engineer work, and ta da !
Unless the engine is designed to disintegrate upon shutdown, it didnt shut down.
Not mutually exclusive. Historically most engine failures happen somewhere between 0% and 100% power VERY rarely when at full power.
Right off the top of my head, spending too much time around critical shaft speed, flow separation from one side of the nozzle and not the other collapses it (some are tough enough to resist, some not), hard starts (well, stops) where ignition stops for an instant and fuel oxy accumulate in the chamber and suddenly ignites all at once poof kaboom... Or screaming combustion instabilities as the pressure drop across the injectors drops... Another classic is a bearing is going on the turbopumps so efficiency drops by 1% at full power but the engine keeps going until you shut off the power, then the turbo spins down and instantly seizes going from 50K rpm to zero in a fraction of a rotation... well, the axle stops, but the blades usually fly off when that happens. Oh and obviously leaky shutoff valves... You engineer those guys to not shut off accidentally, if they leak a little thats better than an uncontrolled accidental shutdown, so leak in the chamber, spark off a hot spot and kaboom. I don't know their plumbing but if they did the old "one set of valves to start, one set to stop" obviously a partial shutoff valve failure could flow broken valve parts into a full speed rotating turbopump. I'd give 50:50 odds I listed the failure mode above. Who knows if they'll recover enough parts in good enough condition to figure out the root cause.
The Space Shuttle carried 28,000lbs to the International Space Station for about $400 million per launch.
LOL you wish it was that cheap. You took total contract cost divided by number of missions for spaceX, why not for space shuttle? Because the numbers don't match your axe to grind. Here I'll do the data gathering and division for you:
From wikipedia "The actual total cost of the shuttle program through 2011, adjusted for inflation, is $196 billion." (this is pure BS, to "do it all over again" would easily cost over 300B, but I'll use the artificially low PR/marketing BS number for the sake of this argument) divided by 135 missions (unsure how to account for disasters) yields 1.452 billion dollars per 28K lb mission absolute minimum, real world is going to be much more.
So you're looking at 1.6B vs 1.5B, not much of a difference given "nasa accounting" thats a rounding error.
There are serious issues why the shuttle program had to end which began in the 80s, so its pointless to debate what if we continued it. For example we lost about 1 shuttle per 50 flights, and the production lines shut down permanently in the 80s. So if we launch until they're all destroyed, we soon would have no launch capability at all, and merely have to farm out to spaceX later, and the only thing waiting does is make stuff more expensive. I suppose we could R+D and reopen the production lines to build more 1970 era space shuttle orbiters, but that will absolutely explode program cost above the "cheap" 1.5B per launch. Or we could R+D even more and build new 2010 era space shuttle orbiters, that would probably be overall a bit cheaper but still boost program cost above 1.5B.
If you wanted to continue the shuttle program, that decision had to be made in the 80s when the last orbiter rolled off the assembly line and the clock started ticking on the program shutdown. Sunday Oct 07 2012 is a bit late to the party to decide the orbiter production line should have been kept open back in April of 1985. First, build a time machine and go back more than a quarter century...
Propeller2 from microchip inc
Well that was embarrassing. That would be Parallax Inc, before the prop came out mid last decade (its old) they were famous for the basic stamp which I guess you'd call the Ardweeeeeeeno of 1990.
Microchip makes the PICs. I was thinking of something along the lines of instead of buying 8 cores of 80 mhz 2005 era propeller for $8, buy 8 PIC24's in 20 pin DIP packages (easy for noobs to prototype) for a bit over a buck a piece and tie the I/O lines together and learn the agonies of multi-processor interfacing...
Comparing it to Pi is a little disingenuous. Reading the copy suggests there is an ARM core, plus some number of co-processors (perhaps like the Cell and its SPEs). That would make it a non-general-purpose processor. To compare apple-to-apples, we'd have to know how it compare to modern GPUs.
As for apples to apples, It's vaporware specs read similar to the old printout of the vaporware specs for the Propeller2 from microchip inc on my desk.
They are nearly identical situations, in fact, both small teams (the original prop was done by one guy, admitedly 6-7 years ago). Gigaflops/sec performance goals, etc.
As for which is the better vaporware product I think you're slightly better off with the parallella story than the prop2 story, but slow working silicon purchased online by CC and delivered by UPS next week always beats fast vapor, so whoever gets there first, wins....
To make parallel computing ubiquitous, developers need access to a platform that is affordable, open, and easy to use.
They promise the latter three, but "access" seems a bit lacking. Also they specifically left out performance but talk it up in separate marketing materials (5 watts for 45 GFLOPs etc)
Some other alternatives optimizing for local maxima in the solution set:
Just simulate in software, if you don't care about speed but want to learn to program parallel. Erlang? They seem to have a fixation on C, why not use the right tool?
Go to opencores.org and stick a zillion cores on a off the shelf FPGA dev board. Or a fat stack of picoblaze or microblaze if you're willing to deal with the annoying licensing hassles (my advice, stick with opencores to avoid legal hassles, the weird licensing for the *blaze family is like the creepy dude in a van offering kids "free" candy)
They seem spread a bit thin based on clicking around the website. They're doing everything but invent hard AI and the warp drive on their website, which is a lot for just 4 people. Their kickstarter seems pretty firmly grounded in comparison.
One of those "infinite spare time" play toys would be to stick a bunch of 6809 cores (or pdp-8s or -11s or Z80s or whatever) on one of my FPGA boards and figure out the glue logic. Anyone with a big enough board could download by VHDL/Verilog and go for it on their own hardware.
Not even the Mayans thought the world would end when their calender did.
Even if they did, whats their track record. Hmm wiped out. Not looking good. You'd think they would have predicted and avoided that.
The classic psychic / mindreader defense. "So whats your name, what brings you here?" "If you're so good at prediction, why don't you tell me?"
I suspect its going to be an action and special effects demo reel with as thin a layer of plot "frosting" as possible. Like the latest star trek movie.
Its kind of like hoping for a Ringo / Aldenata / Posleen movie.. it would just be a sci fi horror gore-fest shoot em up, pretty boring compared to the books.
Why isn't it educational?... without having learned ....
Modern education means you'll pay some at least semi-crooked corporation as much money as they figure they can get you to borrow, in exchange for a sheet of paper you can show to someone who knows nothing about anything other than that a piece of paper qualifies you to have a job. Currently it ranks right up there with "I watched an old episode of NOVA on PBS" and "I have a certificate/associates degree" hard to say which of three three prioritizes lower.
I know it doesn't have much to do with the "real" or "old" definition of education or training, but it does reflect modern reality.
complaining how everything sucks
Fair enough. Four things work:
1) Smart enough to know how to learn, plus internet access = self education. Don't really need much else anymore. Not access to subscription contracted flash websites that happen to be on the internet, not filtered internet, just raw search engine and internet.
2) Printing press seems helpful especially for workbooks (I was just kidding about the whine about papyrus being invented)
3) Improved student:teacher ratio always seems to help
4) Getting the students interested in the topic via social pressure or whatever works to light a spark
"California CEO Meg Whitman told financial analysts today that it will take until 2016 to turn the state around. Surprisingly, Whitman put some of the blame for the state's woes on its IT systems, which she said have hurt its internal operations. To fix its IT problems, Whitman said the state offices are adopting Salesforce and HR system Workday. The state also plans to cut benefits and entitlements. It said it has 2,100 different forms alone; it wants to reduce that by half. 'In every state we're going to benefit from focusing on a smaller number of entitlements that we can invest in and really make matter,' said Whitman."
I donno if its going to be all that different.
10 middlemen retailers all with a policy "we will pricematch any competitors price for the identical model". Well, if walmart is the only retailer on the planet who sells model 13513.2362 then I guess they'll never have to pricematch, will they?
Also add some B+W only models, some multifunction models...
Their metrics are bizarre ...
... if they were using /. UID numbers and ./ Karma and the /. friend/foe network and all that, I bet the results would be far more informative.
I think /. should allow klout linking... I think it would really further my career to be known as highly influential WRT goatse, TRS-80s, and being grouchy.
Interferometer side by side, seriously. Takes a bit of additional support hardware of course.
Gotta wonder what they are flying now. Keep in mind that these huge telescopes are not pointed at the cosmos.
Aside from the political stuff I have a serious scientific question, one end of a scope is the room temp end pointed at the (on average) room temp earth all the time, and the other end of a scope alternates between hot sunlight and frozen deep space every orbit. From a technical perspective, are there modifications to the thermal system required, and if so are they the "expense" they're complaining about? If it's cheaper technologically to continue to point "down" I would imagine there's some interesting earth science they could do.