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rdc12

328 karma · joined August 11, 2013

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rdc12··on You can't fool the optimizer
Matt Godbolt's talk on ray tracers, shows how effective that change can be. Think it was that talk anyway.

https://www.youtube.com/watch?v=HG6c4Kwbv4I

rdc12··on COBOL to Kotlin via Formal Models (IR and Alloy and Golden Master)
With C in the embedded world it is very common to write entire applications that never only use static memory and the stack. Sometime programmers will allow dynamic memory during init only, other times not even then (I tend to favour the never approach, as I can verify that malloc is never called anywhere).
rdc12··on Delimited continuations in lone Lisp
Looks like this other article goes into the details. https://www.matheusmoreira.com/articles/self-contained-lone-...
rdc12··on Drought in Iraq reveals tombs created 2,300 years ago
It's very common that both historical artifacts and natural wonders have been consumed by reservoirs, I suspect it would be almost impossible to avoid this.
rdc12··on I wasted weeks hand optimizing assembly because I benchmarked on random data
Do you have a link to that paper?
rdc12··on Joining Sun Microsystems – 40 years ago (2022)
Do you have a link to that podcast?
rdc12··on Find the oldest line in your repo
For the codebase I was working on today (in C). At first it was just } so filtered those out, then it was /* (no comment detail on that line) so again filter them. Then it was a bunch of #includes.

Not surprising but not insightful at all unfortunately

rdc12··on SVC16: Simplest Virtual Computer
FPGA's also have billions of transistors now, but adding more block memory means removing transistors from something else, such as LUT's, registers, DSP blocks etc.

As always it is a tradeoff, and given many designs don't need much block memory, or need so much memory that external memory is a better choice anyway.

rdc12··on I sent an Ethernet packet
Recently at work I developed a small suite tools (in a mixture of python and shell, running in WSL) that left my boss impressed when he saw me debugging a customers system (IOT).

Then he started asking me to make them accessible to non programmers, and suddenly those tools seemed a lot more than I bargained for.

rdc12··on Why Mount Rainier is the US volcano keeping scientists up at night
Different volcano, but back in the 50's the natural tephra damn on the crater lake of Mount Ruapehu (New Zealand) collapsed triggering a lahar, that ultimately took out the piers of rail bridge near Tangiwai minutes before a passenger train tragically attempted to cross the bridge, resulting in mass casualty's.

So certainly possible for non-expulsive activities to trigger a lahar and for consequences that sound like they are more from a disaster movie then real life to occur.

rdc12··on Scientists find wreckage of ship that tried to warn Titanic of iceberg
And the collision of the RMS Olympic (the first of the three in that family) with the HMS Hawke. As did the coal stoker Arthur Priest

https://en.wikipedia.org/wiki/Arthur_John_Priest

rdc12··on Some statistics about BTRFS compression
That is correct, if the first few records (a virtual block size sorta) (not sure how many off the top of my head) don't compress well, it assumes that the file is not compressible and just writes the data out skipping the compression step.
rdc12··on Caring for the only known full kākāpō feather cloak in the world
That quote doesn't contradict what mkl said, towards the end of the article it does say this thou, "The cloak will be on display in the new museum developed in Perth, set to open in Spring 2024."
rdc12··on Caring for the only known full kākāpō feather cloak in the world
That clip never gets old, Sirocco (the birds name) sure has some attitude.
rdc12··on YouTuber builds his own x-ray machine after $69k hospital bill (2021)
Well most of the politicians don't have a clue that any of that stuff is possible either.
rdc12··on Old imageshack images have a 1:5 chance of showing a Ukranian flag
3 attempts to get a hit for me, in NZ
rdc12··on Hot-code reloading on macOS/arm64 with Zig
Can hot-code reloading coexist well with inlined functions?
rdc12··on ZFS on a single core RISC-V hardware with 512MB
It isn't required (in the strict sense) to keep the dedup table in memory, the problem is that performance is dire when it doesn't. It would be pretty similar to virtual memory thrashing, when the table is not fully in memory.
rdc12··on Predicting the tide with an analog computer made from Lego
Solid plastic might, but would moving water and impacts result in the bricks separating?
rdc12··on Brussels battles old prejudices as it frees unloved river from its vault
What happened to Germany (territory shrinkage and economic sanctions) after WW1 incidentally shows this story pretty well.
rdc12··on What every programmer should know about SSDs
The drive can infer that the LBA hasn't been mapped, since it won't be present in the FTL, there is no need for the OS to inform the drive of this.
rdc12··on What every programmer should know about SSDs
You could use some sort of disk quota system, to make the filesystem artificially smaller than it actually is (trim after applying this change). Or simply insure that you don't exceed 80% - 90% used space.

It it is also worth noting that many SSD's are over-provisioned by the manufacture anyway, in those drives manual over-provisioning might achieve very little anyway.

rdc12··on What every programmer should know about SSDs
The SSD maintains a translation table for all the virtual addresses exposed by the drive, that maps to the underlying flash physical addresses. Any physical address not in that table, is unallocated and the drive can use freely.
rdc12··on Ask HN: Why is the Linux community struggling to implement hibernation?
My old T420 couldn't sleep overnight in Windows 7 (something would trigger a resume), but would sleep fine under Linux and FreeBSD.
rdc12··on What’s the best non-smart TV sold today?
Not sure if this is more or less extreme option, but you could put the TV in a Faraday cage, or build a Faraday cage into your walls.
rdc12··on OpenZFS 2.0
Directly no, but if you moved the data to a new dataset, with a command that preserves the timestamp that would work (rsync -a or zfs send/recv), which could be run from a cronjob.

Compression settings are set at a per dataset level, so applying this to only some files in a dataset isn't practical.

rdc12··on OpenZFS Merged to FreeBSD
From what I have heard, the amount of work needed in porting native encryption to the original FreeBSD port of ZFS was actually what led to this project.
rdc12··on Pilo: Raspberry Pi-Powered Lights-Out Remote Server Management
You could also hook up a GPIO pin to the wires for the power on button
rdc12··on Let's Build a 28-Core Raspberry Pi Cluster
Is the design files available for the rack mounted version (in particular the clip/holder parts).

Been quite keen to build something similar (albeit less nodes) for a little while. I find the homebrew blade style cluster amusing for some reason.

rdc12··on Garmin obtains decryption key after ransomware attack
I can think of an example in New Zealand where an old law (Sedition) was essentially ignored for several decades. A couple years after its first use in a modern setting (early 00's) it was repealed.
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