hot metal oxide @cda@m.hzrd.us

#run

I wonder how many kernel patches are like "this other party fork is impossible to merge but they fixed this one thing for which I am including the patch" ... or is that... uncouth?

Turned out there were no locks around the atomic commit so it was only atomic if it page flipping was synchronous. If another commit came in it would clobber the commit obj and/or abandon the completion event. Vendor solution in the unholy fork was to disable async page flipping to a terrible performance hit. But they also actually fixed the bug later. :facepalm:

Well, this seems like a race condition. If I turn up drm.debug in sysfs, no memory gets leaked. Heisenbugs [sigh]

This seems incredible on mainline though. Current theory is ioctl for page flip seems to perhaps be leaking `struct drm_pending_vblank_event` (bleeding kmalloc-64 slabs). Perhaps a missing send_event* ... maybe based on vblank + async combination.

f'realz tho...

# grep drm_atomic_helper_commit /sys/kernel/debug/kmemleak | wc -l

51838

Well, I'm at the
# cat /sys/kernel/debug/kmemleak
par of my day.
I guess it's my turn to be "it's a kernel bug!" guy.

Spent two hours or more trying to update a vendor's long running unholy Linux kernel fork before realizing it was quicker and simpler to take mainline and patch in the vendor files from the unholy fork. Why are vendors like this? [sigh]

Started on a board layout today. Last board was this multi-rail power supply in... January? Jeeez.

Oh right, I can just change the way mastodon looks. There are like a billion mastodon css classes though so this will take some time.

Alright, I guess I need to get off my dusty rusty and figure out the best way to get raw RGB video frame data out of a hardware mpeg decoder in Linux...

3) Without the interconnects, the neurons could be arbitrarily located, say, outside a skull, distributed around a lab. Something is still having a conscious experience are they not?
Kicker:
4) If 4 is true, then the state being replayed by a computer falls under the same deduction does it not? Cannot it be said that the conscious experience is occuring in two places?

Know:
I) We can record and playback neuronal activity in mice and show they behave as if reliving the recorded experience (overwrite activations)
Imagine:
1) Do the same on a human, recording all state (say 10 minutes), replaying it. A lived experience.
2) Remove the connections between neurons (you are overwriting the activation anyway) and do the replay. This should still be a conscious experience.

Been thinking on this thought experiment a bit recently:

Assume:
A) whatever consciousness is occurs in the matter in your skull
B) consciousness is emergent from the state of neurons and their transitions (even if we don't understand the neuron types or "map")
C) "substrate independence": consciousness is memory and computation regardless of whether it is occuring in silicon or meat.

I've started poking at a SMPS-the-hard-way project. Fully custom controller gateware. So far have: spread-spectrum PWM, zero-cross / sync. rectification, H/L gate control with min-deadtime / shoot-through protection, sigma-delta feedback. Will run it on a completely overkill FPGA because that's what I can get with the supply issues.

#introductions

I design software and hardware systems. I've worked on orbital launch vehicles and satellites. I can talk about "space stuff" all day. I design sub-sea ROV systems for fun.

One day hacking on gateware, the next a byte-code interpreter, the next a PCB, the next a Linux kernel driver, etc. I wrote game engines for a time.

I'm recurrently obsessed with artificial general intelligence (Goertzel-like formulations), artificial life, computational behavior (not ML).

...at least I know who I was when I got up this morning, but I think I must have been changed several times since then...