anonymous-panda

It has many meanings. Terrorism, weaponry and destruction are one meaning. Here are two others:

> The center of rapid or intense development or change. noun

> The starting point or most basic level.

The author used it correctly even though you got triggered by the word.

https://www.wordnik.com/words/ground%20zero

You’re not describing anything different from how Nyquist pops up in analog signals either - sampling and signal will always have jitter and noise. I would recommend reading the linked pdf if you haven’t done so as it gives a number of examples of how Nyquist can screw up your intuition.

> Under the Jones Act, any ship carrying cargo and traveling between ports in the United States, or to the United States from a foreign country, has to be built in America and owned by an American

https://time.com/4961159/what-is-jones-act-puerto-rico/

Yes it also applies to Hawaii:

> Hawaii and Puerto Rico share many similarities. Among those is the devastating effect on island economies of the Jones Act, which prohibits international vessels from carrying cargo between U.S. ports.

https://www.grassrootinstitute.org/2022/08/how-the-jones-act...

The problem is that shipping is the only way to deliver lots of goods to Hawaii and Puerto Rico (origin of shipment doesn’t really matter here). Other states have terrestrial borders and thus don’t care as much.

It’s not about being unlucky, it’s the second thing you point out. It’s not the difference between 100khz and 100.001khz. You’re going to roughly alias at multiples of the sampling frequency, so you can’t tell between 2khz, 10khz, and 100khz which means that even if you collect enough signal, your 1Mhz signal with code running at 1ghz is going to potentially look like a 10khz signal leading you to make the wrong conclusions about where time is being spent.

Remember - profiling tools aren’t even giving you a frequency bin and indicating which samples you see there. It’s giving you a sample and estimating frequency. Most people are not optimizing code that’s running at millions of times per second so it’s not a common problem, but all sorts of wrong conclusions start to get made.

If the 20% is a hotspot yes. If the 20% is because it’s been inlined and split across 100 different call sites each contributing 0.2%, I don’t think it’s so easy to spot.

It’s been a few years but if I recall correctly the fact that there’s variation in the sampling itself makes the aliasing worse not better. At the very least should be no different.

Conversely that naval traffic MUST be done on US-built ships with crews that no how to man them which is a national security thing. I don’t see how allowing foreign built ships ie foreign crews helps with that aspect. Consider that we’re trying to onshore industrial things precisely for that purpose now in preparation for a potential war with China over Taiwan.

I also challenge that it’s also impossibly expensive because it that were the case things in Puerto Rico would cost much more whereas they’re a little bit cheaper than Miami.

https://www.numbeo.com/cost-of-living/compare_cities.jsp?cou...

That’s not to say that the Jones act should have reforms applied, particularly with respect to helping Puerto Rico compete more fairly, but I don’t think it’s clearly one of those totally evil regulations that’s hampering US creativity and ingenuity from flourishing.

You’re talking about profiling a normal running program. If you’re profiling a benchmark that’s always executing the hot path, where exactly the hot path contribution lies becomes less clear. This is because you run into aliasing with the samples being collected at unhelpful points. Maybe if you run long enough you start to see a picture but at 1khz you’re going to have to run for a very long time. The other way aliasing comes into effect is that it becomes to see the impact of “individually cheap” but often executed pieces of code (eg a simple bounds check may not show up even if it’s responsible for a 20% slowdown because the probability of your sampler hitting it is small when that bounds check takes nanoseconds to execute vs your ms profiler sample rate.

Basically a 1ms sampler can pick out a signal that’s 2ms or longer in periodicity if sampled once (all faster signals will get aliased). To get to 1ghz (once a nanosecond) would require capturing 1 million times more samples and you’re still dealing with aliasing screwing up the picture you’re getting (although maybe with stack sampling you get disambiguation to combat aliasing? Not sure).

It’s interesting to me how frequently people will talk about sampling performance profilers and not know about Nyquist.

Given a CPU runs at many GHz but SW sampling profilers run at ~1 or even maximum 10khz, it’s really hard to write software if you’re targeting processing at MHz rates.

> Look at the treatment of Boeing after 2 airplane crashes for example

Well, Boeing was taken to task not for trying to innovate and making mistakes but for lying (fraud) and regulatory capture of the FAA (something a smaller competitor can’t do and in fact likely prevents smaller competitors). As an investor, the former should make you wary and as a flier the latter should make you scared.

> The US has particulate air pollution that is half of South Korea's and a quarter of China. It is a pretty reasonable guess that air pollution would be mostly industrial production that the US would shut down for environmental concerns.

Considering the primary stated motivator by many industrial companies for outsourcing to China was labor costs and not environmental regulations, I wouldn’t be so confident in this claim. This is borne out by research which tries to compare environmental regulations across regulatory regimes:

> In our newest research, we compared risk regulation in China and the United States, and we have also found a more complex pattern that does not support the longstanding conventional view of U.S. regulation being much more stringent than in China.

https://www.theregreview.org/2021/12/20/xu-wiener-comparing-...

> * US labour laws are an impediment. That new fab plant that TSMC was trying to build in the US seemed to be falling over because it was illegal to use skilled, experienced labour.

I don’t know what you’re referring to but generally the problems with such endeavors are that skilled work in a different cultural and regulatory environment is challenging and this applies to European companies trying to enter the US market and US companies trying to enter other markets for the first time too, especially when it comes to complex technical projects. Also, the primary labor laws that tend to be an impediment are things like worker safety and compensation. The latter is a bit less important for highly skilled labor but safety is certainly not. I think the bigger problem is trade arrangements that have long ignored these rather than estimating the cost worker safety regulations impose and taxing products from regimes that don’t have good regulations.

> The US is seeing declines in per-capita energy availability and flat actual production. That is almost certainly a policy choice linked to anti-fossil-fuel ideologies, Asia has been seeing seeing crazy growth. It is hard to do energy-intensive activities like manufacturing in an environment where securing energy is a battle.

That seems like a leap when China is installing a lot of nuclear and solar energy. Yes they’re also still building coal plants but that’s intended to be as a backstop for solar until they build enough nuclear capacity.

> It should be a literal embarrassment that we're being outdone at capitalism by nominal communists

China hasn’t really been a communist country in anything more than name for quite a while and is actually pretty capitalist despite their own claims to the contrary (they still like to pretend): https://www.cato.org/policy-report/january/february-2013/how...

You seem to like to state something that may be true but jump to a conclusion without any supporting evidence for making that claim. I’ve noticed Tucker Carlson does the same thing (at least on the Lex Friedman interview as I generally find him an insufferable blowhard) and it’s quite annoying.

For all the faults of the Jones Act, I don’t think that explains the challenges of US ship building. If anything, it keeps US ship building efforts alive when foreign ships would have killed it.

I think the hard part of it is that x86 only has one atomic ordering and none of the other modes do anything. As such, it’s really hard to build intuition about it unless you spend a lot of time writing such code on ARM which wasn’t that common in the industry and today most people use higher level abstractions.

By databases, do you mean those running on DEC Alphas? Cause that was a niche system that few would have had experience with. If you meant to compare in terms if consistency semantically, sure but there’s meaningful differences between database consistency semantics of concurrent transactions and atomic ordering in a multithreaded concept.

Java’s memory model “wrestling” was about defining it formally in an era of multithreading and it’s largely sequentially consistent - no weakly consistent ordering allowed.

The c++ memory model was definitely the first large scale adoption of weaker consistency models I’m aware of and was done so that ARM CPUs could be properly optimized for since this was c++11 when mobile CPUs were very much front of mind. Weak consistency remains really difficult to reason about and even harder to play around with if you primarily work with x86 and there’s very little tooling around to validate that can help you get confidence about whether your code is correct. Of course, you can follow common “patterns” (eg loads are always acquire and stores are release), but fully grokking correctness and being able to play with the model in interesting ways is no small task no matter how many learning resources are out there.

How far into the future? I feel like I’ve been hearing about unikernels for over a decade now but I’ve yet to see them adopted in any real way by any large companies which in theory would benefit the most by the cost savings and improved security these should provide.

Are there any risks associated with just saying you have competing offers from other companies that have the shape of the contract you’re negotiating for?