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A little while back, I wrote that we shouldn't say "auth" but should use other terms instead. I stand by my argument in general, but it also has another side to it: my suggested terminology makes sense in some domains, but not in all domains. And that's because terminology isn't—and can't be—universal. After I wrote that blog post, I got an email from someone who had a really good point: the word "login" is often confused for "username"! My terminology suggestion doesn't work in all cases, so what's the right word to use instead? Unfortunately... there isn't one. There's no one pair of words that will work perfectly. Terminology makes sense relative to the context it's in. If I say "node" to you, what does that mean? My guess is you will think of either a node in a network/graph or a node as in a server. But you could also think of a lymph node or myriad other things! The other term you could use in a graph context is "vertex". This is often clearer, but it runs into issues if you're...
5 months ago

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More from ntietz.com blog - technically a blog

Taking a break

I've been publishing at least one blog post every week on this blog for about 2.5 years. I kept it up even when I was very sick last year with Lyme disease. It's time for me to take a break and reset. This is the right time, because the world is very difficult for me to move through right now and I'm just burnt out. I need to focus my energy on things that give me energy and right now, that's not writing and that's not tech. I'll come back to this, and it might look a little different. This is my last post for at least a month. It might be longer, if I still need more time, but I won't return before the end of May. I know I need at least that long to heal, and I also need that time to focus on music. I plan to play a set at West Philly Porchfest, so this whole month I'll be prepping that set. If you want to follow along with my music, you can find it on my bandcamp (only one track, but I'll post demos of the others that I prepare for Porchfest as they come together). And if you want to reach out, my inbox is open. Be kind to yourself. Stay well, drink some water. See you in a while.

6 days ago 2 votes
Measuring my Framework laptop's performance in 3 positions

A few months ago, I was talking with a friend about my ergonomic setup and they asked if being vertical helps it with cooling. I wasn't sure, because it seems like it could help but it was probably such a small difference that it wouldn't matter. So, I did what any self-respecting nerd would do: I procrastinated. The question didn't leave me, though, so after those months passed, I did the second thing any self-respecting nerd would do: benchmarks. The question and the setup What we want to find out is whether or not the position of the laptop would affect its CPU performance. I wanted to measure it in three positions: normal: using it the way any normal person uses their laptop, with the screen and keyboard at something like a 90-degree angle closed: using it like a tech nerd, closed but plugged into a monitor and peripherals vertical: using it like a weird blogger who has sunk a lot of time into her ergonomic setup and wants to justify it even further My hypothesis was that using it closed would slightly reduce CPU performance, and that using it normal or vertical would be roughly the same. For this experiment, I'm using my personal laptop. It's one of the early Framework laptops (2nd batch of shipments) which is about four years old. It has an 11th gen Intel CPU in it, the i7-1165G7. My laptop will be sitting on a laptop riser for the closed and normal positions, and it will be sitting in my ergonomic tray for the vertical one. For all three, it will be connected to the same set of peripherals through a single USB-C cable, and the internal display is disabled for all three. Running the tests I'm not too interested in the initial boost clock. I'm more interested in what clock speeds we can sustain. What happens under a sustained, heavy load, when we hit a saturation point and can't shed any more heat? To test that, I'm doing a test using heavy CPU load. The load is generated by stress-ng, which also reports some statistics. Most notably, it reports CPU temperatures and clock speeds during the tests. Here's the script I wrote to make these consistent. To skip the boost clock period, I warm it up first with a 3-minute load Then I do a 5-minute load and measure the CPU clock frequency and CPU temps every second along the way. #!/bin/bash # load the CPU for 3 minutes to warm it up sudo stress-ng --matrix $2 -t 3m --tz --raplstat 1 --thermalstat 1 -Y warmup-$1.yaml --log-file warmup-$1.log --timestamp --ignite-cpu # run for 5 minutes to gather our averages sudo stress-ng --matrix $2 -t 5m --tz --raplstat 1 --thermalstat 1 -Y cputhermal-$1.yaml --log-file cputhermal-$1.log --timestamp --ignite-cpu We need sudo since we're using an option (--ignite-cpu) which needs root privileges[1] and attempts to make the CPU run harder/hotter. Then we specify the stressor we're using with --matrix $2, which does some matrix calculations over a number of cores we specify. The remaining options are about reporting and logging. I let the computer cool for a minute or two between each test, but not for a scientific reason. Just because I was doing other things. Since my goal was to saturate the temperatures, and they got stable within each warmup period, cooldowh time wasn't necessary—we'd warm it back up anyway. So, I ran this with the three positions, and with two core count options: 8, one per thread on my CPU; and 4, one per physical core on my CPU. The results Once it was done, I analyzed the results. I took the average clock speed across the 5 minute test for each of the configurations. My hypothesis was partially right and partially wrong. When doing 8 threads, each position had different results: Our baseline normal open position had an average clock speed of 3.44 GHz and an average CPU temp of 91.75 F. With the laptop closed, the average clock speed was 3.37 GHz and the average CPU temp was 91.75 F. With the laptop open vertical, the average clock speed was 3.48 GHz and the average CPU temp was 88.75 F. With 4 threads, the results were: For the baseline normal open position, the average clock speed was 3.80 GHz with average CPU temps of 91.11 F. With the laptop closed, the average clock speed was 3.64 GHz with average CPU temps of 90.70 F. With the laptop open vertical, the average clock speed was 3.80 GHz with average CPU temps of 86.07 F. So, I was wrong in one big aspect: it does make a clearly measurable difference. Having it open and vertical reduces temps by 3 degrees in one test and 5 in the other, and it had a higher clock speed (by 0.05 GHz, which isn't a lot but isn't nothing). We can infer that, since clock speeds improved in the heavier load test but not in the lighter load test, that the lighter load isn't hitting our thermal limits—and when we do, the extra cooling from the vertical position really helps. One thing is clear: in all cases, the CPU ran slower when the laptop was closed. It's sorta weird that the CPU temps went down when closed in the second test. I wonder if that's from being able to cool down more when it throttled down a lot, or if there was a hotspot that throttled the CPU but which wasn't reflected in the temp data, maybe a different sensor. I'm not sure if having my laptop vertical like I do will ever make a perceptible performance difference. At any rate, that's not why I do it. But it does have lower temps, and that should let my fans run less often and be quieter when they do. That's a win in my book. It also means that when I run CPU-intensive things (say hi to every single Rust compile!) I should not close the laptop. And hey, if I decide to work from my armchair using my ergonomic tray, I can argue it's for efficiency: boss, I just gotta eke out those extra clock cycles. I'm not sure that this made any difference on my system. I didn't want to rerun the whole set without it, though, and it doesn't invalidate the tests if it simply wasn't doing anything. ↩

a week ago 2 votes
The five stages of incident response

The scene: you're on call for a web app, and your pager goes off. Denial. No no no, the app can't be down. There's no way it's down. Why would it be down? It isn't down. Sure, my pager went off. And sure, the metrics all say it's down and the customer is complaining that it's down. But it isn't, I'm sure this is all a misunderstanding. Anger. Okay so it's fucking down. Why did this have to happen on my on-call shift? This is so unfair. I had my dinner ready to eat, and *boom* I'm paged. It's the PM's fault for not prioritizing my tech debt, ugh. Bargaining. Okay okay okay. Maybe... I can trade my on-call shift with Sam. They really know this service, so they could take it on. Or maybe I can eat my dinner while we respond to this... Depression. This is bad, this is so bad. Our app is down, and the customer knows. We're totally screwed here, why even bother putting it back up? They're all going to be mad, leave, the company is dead... There's not even any point. Acceptance. You know, it's going to be okay. This happens to everyone, apps go down. We'll get it back up, and everything will be fine.

2 weeks ago 13 votes
Python is an interpreted language with a compiler

After I put up a post about a Python gotcha, someone remarked that "there are very few interpreted languages in common usage," and that they "wish Python was more widely recognized as a compiled language." This got me thinking: what is the distinction between a compiled or interpreted language? I was pretty sure that I do think Python is interpreted[1], but how would I draw that distinction cleanly? On the surface level, it seems like the distinction between compiled and interpreted languages is obvious: compiled languages have a compiler, and interpreted languages have an interpreter. We typically call Java a compiled language and Python an interpreted language. But on the inside, Java has an interpreter and Python has a compiler. What's going on? What's an interpreter? What's a compiler? A compiler takes code written in one programming language and turns it into a runnable thing. It's common for this to be machine code in an executable program, but it can also by bytecode for VM or assembly language. On the other hand, an interpreter directly takes a program and runs it. It doesn't require any pre-compilation to do so, and can apply a variety of techniques to achieve this (even a compiler). That's where the distinction really lies: what you end up running. An interpeter runs your program, while a compiler produces something that can run later[2] (or right now, if it's in an interpreter). Compiled or interpreted languages A compiled language is one that uses a compiler, and an interpreted language uses an interpreter. Except... many languages[3] use both. Let's look at Java. It has a compiler, which you feed Java source code into and you get out an artifact that you can't run directly. No, you have to feed that into the Java virtual machine, which then interprets the bytecode and runs it. So the entire Java stack seems to have both a compiler and an interpreter. But it's the usage, that you have to pre-compile it, that makes it a compiled language. And similarly is Python[4]. It has an interpreter, which you feed Python source code into and it runs the program. But on the inside, it has a compiler. That compiler takes the source code, turns it into Python bytecode, and then feeds that into the Python virtual machine. So, just like Java, it goes from code to bytecode (which is even written to the disk, usually) and bytecode to VM, which then runs it. And here again we see the usage, where you don't pre-compile anything, you just run it. That's the difference. And that's why Python is an interpreted language with a compiler! And... so what? Ultimately, why does it matter? If I can do cargo run and get my Rust program running the same as if I did python main.py, don't they feel the same? On the surface level, they do, and that's because it's a really nice interface so we've adopted it for many interactions! But underneath it, you see the differences peeping out from the compiled or interpreted nature. When you run a Python program, it will run until it encounters an error, even if there's malformed syntax! As long as it doesn't need to load that malformed syntax, you're able to start running. But if you cargo run a Rust program, it won't run at all if it encounters an error in the compilation step! It has to run the entire compilation process before the program will start at all. The difference in approaches runs pretty deep into the feel of an entire toolchain. That's where it matters, because it is one of the fundamental choices that everything else is built around. The words here are ultimately arbitrary. But they tell us a lot about the language and tools we're using. * * * Thank you to Adam for feedback on a draft of this post. It is worth occasionally challenging your own beliefs and assumptions! It's how you grow, and how you figure out when you are actually wrong. ↩ This feels like it rhymes with async functions in Python. Invoking a regular function runs it immediately, while invoking an async function creates something which can run later. ↩ And it doesn't even apply at the language level, because you could write an interpreter for C++ or a compiler for Hurl, not that you'd want to, but we're going to gloss over that distinction here and just keep calling them "compiled/interpreted languages." It's how we talk about it already, and it's not that confusing. ↩ Here, I'm talking about the standard CPython implementation. Others will differ in their details. ↩

3 weeks ago 15 votes
Typing using my keyboard (the other kind)

I got a new-to-me keyboard recently. It was my brother's in school, but he doesn't use it anymore, so I set it up in my office. It's got 61 keys and you can hook up a pedal to it, too! But when you hook it up to the computer, you can't type with it. I mean, that's expected—it makes piano and synth noises mostly. But what if you could type with it? Wouldn't that be grand? (Ha, grand, like a pian—you know, nevermind.) How do you type on a keyboard? Or more generally, how do you type with any MIDI device? I also have a couple of wind synths and a MIDI drum pad, can I type with those? The first and most obvious idea is to map each key to a letter. The lowest key on the keyboard could be 'a'[1], etc. This kind of works for a piano-style keyboard. If you have a full size keyboard, you get 88 keys. You can use 52 of those for the letters you need for English[2] and 10 for digits. Then you have 26 left. That's more than enough for a few punctuation marks and other niceties. It only kind of works, though, because it sounds pretty terrible. You end up making melodies that don't make a lot of sense, and do not stay confined to a given key signature. Plus, this assumes you have an 88 key keyboard. I have a 61 key keyboard, so I can't even type every letter and digit! And if I want to write some messages using my other instruments, I'll need something that works on those as well. Although, only being able to type 5 letters using my drums would be pretty funny... Melodic typing The typing scheme I settled on was melodic typing. When you write your message, it should correspond to a similarly beautiful[3] melody. Or, conversely, when you play a beautiful melody it turns into some text on your computer. The way we do this is we keep track of sequences of notes. We start with our key, which will be the key of C, the Times New Roman of key signatures. Then, each note in the scale is has its scale degree: C is 1, D is 2, etc. until B is 7. We want to use scale degree, so that if we jam out with others, we can switch to the appropriate key and type in harmony with them. Obviously. We assign different computer keys to different sequences of these scale degrees. The first question is, how long should our sequences be? If we have 1-note sequences, then we can type 7 keys. Great for some very specific messages, but not for general purpose typing. 2-note sequences would give us 49 keys, and 3-note sequences give us 343. So 3 notes is probably enough, since it's way more than a standard keyboard. But could we get away with the 49? (Yes.) This is where it becomes clear why full Unicode support would be a challenge. Unicode has 155,063 characters (according to wikipedia). To represent the full space, we'd need at least 7 notes, since 7^7 is 823,543. You could also use a highly variable encoding, which would make some letters easy to type and others very long-winded. It could be done, but then the key mapping would be even harder to learn... My first implementation used 3-note sequences, but the resulting tunes were... uninspiring, to say the least. There was a lot of repetition of particular notes, which wasn't my vibe. So I went back to 2-note sequences, with a pared down set of keys. Instead of trying to represent both lowercase and uppercase letters, we can just do what keyboards do, and represent them using a shift key[4]. My final mapping includes the English alphabet, numerals 0 to 9, comma, period, exclamation marks, spaces, newlines, shift, backspace, and caps lock—I mean, obviously we're going to allow constant shouting. This lets us type just about any message we'd want with just our instrument. And we only used 44 of the available sequences, so we could add even more keys. Maybe one of those would shift us into a 3-note sequence. The key mapping The note mapping I ended up with is available in a text file in the repo. This mapping lets you type anything you'd like, as long as it's English and doesn't use too complicated of punctuation. No contractions for you, and—to my chagrin—no em dashes either. The key is pretty helpful, but even better is a dynamic key. When I was trying this for the first time, I had two major problems: I didn't know which notes would give me the letter I wanted I didn't know what I had entered so far (sometimes you miss a note!) But we can solve this with code! The UI will show you which notes are entered so far (which is only ever 1 note, for the current typing scheme), as well as which notes to play to reach certain keys. It's basically a peek into the state machine behind what you're typing! An example: "hello world" Let's see this in action. As all programmers, we're obligated by law to start with "hello, world." We can use our handy-dandy cheat sheet above to figure out how to do this. "Hello, world!" uses a pesky capital letter, so we start with a shift. C C Then an 'h'. D F Then we continue on for the rest of it and get: D C E C E C E F A A B C F G E F E B E C C B A B Okay, of course this will catch on! Here's my honest first take of dooting out those notes from the translation above. Hello, world! I... am a bit disappointed, because it would have been much better comedy if it came out like "HelLoo wrolb," but them's the breaks. Moving on, though, let's make this something musical. We can take the notes and put a basic rhythm on them. Something like this, with a little swing to it. By the magic of MIDI and computers, we can hear what this sounds like. maddie marie · Hello, world! (melody) Okay, not bad. But it's missing something... Maybe a drum groove... maddie marie · Hello, world! (w/ drums) Oh yeah, there we go. Just in time to be the song of the summer, too. And if you play the melody, it enters "Hello, world!" Now we can compose music by typing! We have found a way to annoy our office mates even more than with mechanical keyboards[5]! Other rejected neglected typing schemes As with all great scientific advancements, other great ideas were passed by in the process. Here are a few of those great ideas we tried but had to abandon, since we were not enough to handle their greatness. A chorded keyboard. This would function by having the left hand control layers of the keyboard by playing a chord, and then the right hand would press keys within that layer. I think this one is a good idea! I didn't implement it because I don't play piano very well. I'm primarily a woodwind player, and I wanted to be able to use my wind synth for this. Shift via volume! There's something very cathartic about playing loudly to type capital letters and playing quietly to print lowercase letters. But... it was pretty difficult to get working for all instruments. Wind synths don't have uniform velocity (the MIDI term for how hard the key was pressed, or how strong breath was on a wind instrument), and if you average it then you don't press the key until after it's over, which is an odd typing experience. Imagine your keyboard only entering a character when you release it! So, this one is tenable, but more for keyboards than for wind synths. It complicated the code quite a bit so I tossed it, but it should come back someday. Each key is a key. You have 88 keys on a keyboard, which definitely would cover the same space as our chosen scheme. It doesn't end up sounding very good, though... Rhythmic typing. This is the one I'm perhaps most likely to implement in the future, because as we saw above, drums really add something. I have a drum multipad, which has four zones on it and two pedals attached (kick drum and hi-hat pedal). That could definitely be used to type, too! I am not sure the exact way it would work, but it might be good to quantize the notes (eighths or quarters) and then interpret the combination of feet/pads as different letters. I might take a swing at this one sometime. Please do try this at home I've written previously about how I was writing the GUI for this. The GUI is now available for you to use for all your typing needs! Except the ones that need, you know, punctuation or anything outside of the English alphabet. You can try it out by getting it from the sourcehut repo (https://git.sr.ht/~ntietz/midi-keys). It's a Rust program, so you run it with cargo run. The program is free-as-in-mattress: it's probably full of bugs, but it's yours if you want it. Well, you have to comply with the license: either AGPL or the Gay Agenda License (be gay, do crime[6]). If you try it out, let me know how it goes! Let me know what your favorite pieces of music spell when you play them on your instrument. Coincidentally, this is the letter 'a' and the note is A! We don't remain so fortunate; the letter 'b' is the note A#. ↩ I'm sorry this is English only! But, you could to the equivalent thing for most other languages. Full Unicode support would be tricky, I'll show you why later in the post. ↩ My messages do not come out as beautiful melodies. Oops. Perhaps they're not beautiful messages. ↩ This is where it would be fun to use an organ and have the lower keyboard be lowercase and the upper keyboard be uppercase. ↩ I promise you, I will do this if you ever make me go back to working in an open office. ↩ For any feds reading this: it's a joke, I'm not advocating people actually commit crimes. What kind of lady do you think I am? Obviously I'd never think that civil disobedience is something we should do, disobeying unjust laws, nooooo... I'm also never sarcastic. ↩

a month ago 15 votes

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yesterday 5 votes
a whippet waypoint

Hey peoples! Tonight, some meta-words. As you know I am fascinated by compilers and language implementations, and I just want to know all the things and implement all the fun stuff: intermediate representations, flow-sensitive source-to-source optimization passes, register allocation, instruction selection, garbage collection, all of that. It started long ago with a combination of curiosity and a hubris to satisfy that curiosity. The usual way to slake such a thirst is structured higher education followed by industry apprenticeship, but for whatever reason my path sent me through a nuclear engineering bachelor’s program instead of computer science, and continuing that path was so distasteful that I noped out all the way to rural Namibia for a couple years. Fast-forward, after 20 years in the programming industry, and having picked up some language implementation experience, a few years ago I returned to garbage collection. I have a good level of language implementation chops but never wrote a memory manager, and Guile’s performance was limited by its use of the Boehm collector. I had been on the lookout for something that could help, and when I learned of it seemed to me that the only thing missing was an appropriate implementation for Guile, and hey I could do that!Immix I started with the idea of an -style interface to a memory manager that was abstract enough to be implemented by a variety of different collection algorithms. This kind of abstraction is important, because in this domain it’s easy to convince oneself that a given algorithm is amazing, just based on vibes; to stay grounded, I find I always need to compare what I am doing to some fixed point of reference. This GC implementation effort grew into , but as it did so a funny thing happened: the as a direct replacement for the Boehm collector maintained mark bits in a side table, which I realized was a suitable substrate for Immix-inspired bump-pointer allocation into holes. I ended up building on that to develop an Immix collector, but without lines: instead each granule of allocation (16 bytes for a 64-bit system) is its own line.MMTkWhippetmark-sweep collector that I prototyped The is funny, because it defines itself as a new class of collector, fundamentally different from the three other fundamental algorithms (mark-sweep, mark-compact, and evacuation). Immix’s are blocks (64kB coarse-grained heap divisions) and lines (128B “fine-grained” divisions); the innovation (for me) is the discipline by which one can potentially defragment a block without a second pass over the heap, while also allowing for bump-pointer allocation. See the papers for the deets!Immix papermark-regionregionsoptimistic evacuation However what, really, are the regions referred to by ? If they are blocks, then the concept is trivial: everyone has a block-structured heap these days. If they are spans of lines, well, how does one choose a line size? As I understand it, Immix’s choice of 128 bytes was to be fine-grained enough to not lose too much space to fragmentation, while also being coarse enough to be eagerly swept during the GC pause.mark-region This constraint was odd, to me; all of the mark-sweep systems I have ever dealt with have had lazy or concurrent sweeping, so the lower bound on the line size to me had little meaning. Indeed, as one reads papers in this domain, it is hard to know the real from the rhetorical; the review process prizes novelty over nuance. Anyway. What if we cranked the precision dial to 16 instead, and had a line per granule? That was the process that led me to Nofl. It is a space in a collector that came from mark-sweep with a side table, but instead uses the side table for bump-pointer allocation. Or you could see it as an Immix whose line size is 16 bytes; it’s certainly easier to explain it that way, and that’s the tack I took in a .recent paper submission to ISMM’25 Wait what! I have a fine job in industry and a blog, why write a paper? Gosh I have meditated on this for a long time and the answers are very silly. Firstly, one of my language communities is Scheme, which was a research hotbed some 20-25 years ago, which means many practitioners—people I would be pleased to call peers—came up through the PhD factories and published many interesting results in academic venues. These are the folks I like to hang out with! This is also what academic conferences are, chances to shoot the shit with far-flung fellows. In Scheme this is fine, my work on Guile is enough to pay the intellectual cover charge, but I need more, and in the field of GC I am not a proven player. So I did an atypical thing, which is to cosplay at being an independent researcher without having first been a dependent researcher, and just solo-submit a paper. Kids: if you see yourself here, just go get a doctorate. It is not easy but I can only think it is a much more direct path to goal. And the result? Well, friends, it is this blog post :) I got the usual assortment of review feedback, from the very sympathetic to the less so, but ultimately people were confused by leading with a comparison to Immix but ending without an evaluation against Immix. This is fair and the paper does not mention that, you know, I don’t have an Immix lying around. To my eyes it was a good paper, an , but, you know, just a try. I’ll try again sometime.80% paper In the meantime, I am driving towards getting Whippet into Guile. I am hoping that sometime next week I will have excised all the uses of the BDW (Boehm GC) API in Guile, which will finally allow for testing Nofl in more than a laboratory environment. Onwards and upwards! whippet regions? paper??!?

2 days ago 6 votes
Stress And Programming

Having spent four decades as a programmer in various industries and situations, I know that modern software development processes are far more stressful than when I started. It's not simply that developing software today is more complex than it was back in 1981. In that early decade, none

2 days ago 5 votes
Espressif’s Automatic Reset

In previous articles, we saw how to use “real” UART, and looked into the trick used by Arduino to automatically reset boards when uploading firmware. Today, we’ll look into how Espressif does something similar, using even more tricks. “Real” UART on the Saola As usual, let’s first simply connect the UART adapter. Again, we connect … Continue reading Espressif’s Automatic Reset → The post Espressif’s Automatic Reset appeared first on Quentin Santos.

2 days ago 5 votes
How I built a chatbot with my dog

Lessons for AI prompting and retrieval

2 days ago 4 votes