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Comment: Re:Why do Windows programs just run? (Score 1) 120

by bn557 (#48895601) Attached to: Linus Fixes Kernel Regression Breaking Witcher 2

Actually, with VERY few exceptions, you can run very old userspaces with new kernels. There have been a few 'fixes' that broke old userspaces (by exposing bugs in userspace that weren't triggered pre-fix), but there's a very strict, never break userspace rule. Sometimes you have to set the correct kernel build time options, but it's expected of a person doing that to know what they're doing, or to trust their distro to know what they're doing.

Look at the recent Linux Wireless mailing list... A few weeks ago, the ability to use 'Wireless Extension Compatability' to control wireless was made unselectable. They have been marked deprecated for YEARS(2008), and are now causing problems with supporting newer wifi features. This was very firmly 'NACKED' by Linus, and the wireless tree has to continue supporting an old, broken, way to control wireless devices.

There are also options you can configure in the kernel like 'COMPAT_VDSO' which work around 1 released version of GLIBC (2.3.3), which was also backported to OpenSuse 9.

I know that it may not have been until the 2.6 era that this became truly 'written in stone' law, but it's always been a pretty firm 'rule'. Hence I can still run a.out binaries on my 64bit system. 'ELF' binaries were added around 2.0 (15-20 years ago?), and have been the default since some time between then and now. Still, a.out support will always live on, because you don't break the kernel to userspace abi.

Comment: Re:Why do Windows programs just run? (Score 1) 120

by bn557 (#48895407) Attached to: Linus Fixes Kernel Regression Breaking Witcher 2

This has been a perpetual problem on my Lenovo W510. In one release, it did multiple steps, in the next one, no backlight control at all. I add some kernel command line options and get a crappy 4 step backlight. In the next release, I have to remove those options because my backlight didn't turn on at all with them. Now no working backlight controls (using the FN+Home/End combo on my laptop keyboard). I poke in the /sys sysfs mount at the backlight control that's registered, and can control the backlight that way. I've been following the ACPI development mailing list and this is a perpetual topic of confrontation.

There are lots of proposed fixes that would just resolve it, but they can't be accepted because they break userspace. The whole problem stems from the Laptop bios. In some cases, the bios will advertise ACPI methods to control the backlight, while the GPU driver exposes the controls as well. Depending on the particular bios version (and sometimes even bios settings), the keypress might, in bios, change the brightness, then report the keypress, or it might report the keypress and depend on the OS to use the ACPI interface to control the backlight, or it might depend on the OS to use the GPU driver interface to control the backlight. On some of the systems, the ACPI interface is sometimes broken, and on some, there are multiple controls (for display port and all the other possible display connections built into the system) with no clear way to determine which one to actually use. Some bioses report to work with 'Windows 2012' but actually completely don't. Some ONLY work with that, but report they work with older ones.

From what I recall of the discussion, Windows 8 deals with this by punting the actual event handling to the GPU drivers, expecting them to know how to handle the hardware.

Similar bugs can be seen in Windows if your run a newer version on hardware designed for a previous version (I saw this running Windows 7 on hardware designed for Windows XP, an old Dell laptop).

I find it kinda crazy that every single other feature of my laptop works perfectly (FIngerprint reader, color calibration, wimax radio {none of which I actually ever use}) while backlight which seems so simple (Press button, change brightness) is in a perpetual state of brokenness.

Comment: Re:Joyent unfit to lead them? (Score 1) 254

by bn557 (#48533135) Attached to: Node.js Forked By Top Contributors

These 'trivial' changes often cause merge conflicts with other trees. If people are developing against the 'pre change' tree, any changes around the comments might need manual merging. Manual merging introduces additional opportunities for mistakes. I see trivial comment patches like this bounced on these exact grounds in watching active linux driver changes; particularly if you watch a new vendor driver submitted to the staging tree, and then watch it get cleaned up to be in-line with the kernel's coding style.

As far as this PARTICULAR patch being dropped, it probably could have been handled more in line with 'NACK: We'll set a date in the future to do a comment cleaning and have everyone rebase on that', but my first reaction isn't that the developer who declined it is sexist (or whatever the particular flavor of discrimination is). From my PERSONAL Point of view, a change should provide value, and I *PERSONALLY* don't see value in a change like this. A typo fix maybe, but this is not a typo.

User Journal

Journal: Entry 2

Journal by bn557

Well, I missed my 10 year journal anniversary. Maybe I'll catch the 20th anniversary.

Does anyone every read these?

Comment: Re:The US slides back to the caves (Score 1) 528

by bn557 (#47768971) Attached to: Limiting the Teaching of the Scientific Process In Ohio

The reason I've always heard is pure cost to convert. All the signs, all the cars, everything that uses distances (all the laws would have to be 'amended' to the new units), etc, etc. There is a LOT of infrastructure in the US. It's a physically large country. Even 'phasing' it in is a HUGE undertaking and would take years if not decades to complete.

I am 100% in support of us converting, but I'm glad I don't have to be one of the people that's going to coordinate the madhouse it's going to be when it's finally decided upon and started.

Comment: Re:Unsafe at any speed (above 100 MPH)... (Score 1) 443

by bn557 (#47436635) Attached to: The First Person Ever To Die In a Tesla Is a Guy Who Stole One

the difference is, it doesn't take the same energy. In the kinetic energy equation, look at the V^2 term. If you start at velocity X, and increase your speed A, your resultant velocity component will be (X + A)^2. Multiplying that out, you get X^2 +2AX + A^2. To go from 0 to 10 mph, you have to add 2 * 10 * 0 + 10 ^ 2 = 100 units (I don't remember the American unit applicable here). To go from 90 to 100, you have to add 2 * 10 * 90 + 10 ^ 2 = 1900 energy units. It takes 19x as much energy to increase speed 10 mph at 90mph IGNORING DRAG.

The X^2 gets ignored because we're only considering the amount of energy we have to ADD to go from X to X + A, and the KE at Vx will end up canceling out the X^2 in the resulting equation subtractions.

Comment: it is new... in a way. (Score 2, Informative) 111

by jhfry (#44569527) Attached to: Wireless Devices Go Battery-Free With New Communication Technique

Sure backscatter has been done... But it always used known frequencies as the signal source. This will pick up any ambient ref noise and use it to generate a new signal.

Essentially, you could embed a transmitter anywhere without concern for a power source (assuming there are other transmitters around).

Anyone can make an omelet with eggs. The trick is to make one with none.

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