I'll correct myself: it sounds good for about 5 seconds before you think about it and realize it's an unworkable idea which creates more problems than it solves.
I also did that for some time, I just don't perceived clocks to have a single point that is up and mentally rotated clocks all the time. The hours just lost their meaning beyond their numerical value.
Most computer PSUs have a fuse inside, and it is quite easy to replace them.
I know because many moons ago I blew one, in the era when PSUs had a toggle between 120V and 230V, and I set it to 120V in a country that runs at 230V...
> The plugs also prevent mixing voltage and amperage. The typical two vertical blades (5-15) are for 15 amp circuits. 20 amp circuits (5-20) have one horizontal + one vertical blade. The receptacle has a T shaped slot to match - that way you can plug a low-amp device into a high-amp circuit but not the reverse.
Alternatively you can just run everything at 230V and then you don't need a million different plugs as any wall socket can provide up to 3.5 kW, enough for any home appliance except for the most power hungry ovens and IH stoves.
Rewiring an entire country is a wee bit expensive. Even if the wires are rated to 300V (they usually are), transformers would have to be replaced, and they cost quite a bit. Also different sockets and circuit breakers, and a whole lot of billable hours by licensed electricians.
(But changing the voltage is easy compared to changing the mains frequency. Japan still has to live with 50Hz in one half of the country, and 60Hz in the other.)
The transformers are fine as they are. We already have 240VAC in the typical US home: Two legs of 120v, with one being 180° out of phase. That part exists and it works fine -- the big industrious parts of the infrastructure are already supplying 240v.
US 240v is a bit different than the way the rest of the world usually does it, where they have 1 leg of 240v and 1 neutral, but AFAICT that detail is not a big deal for the stuff that actually uses electricity.
The wire itself, broadly-speaking, is fine.
Suppose we decided that tomorrow at noon to begin the move to 240v.
We just refactor our breaker panels and update to some new objectively-good whiz-bang outlet format (because we would certainly never borrow existing designs from anywhere else on the planet; we in the States have a big problem with Not Invented Here when it comes to policy), and finally get rid of twist-in Edison light bulb sockets, and that part is done.
But then all kinds of stuff doesn't work anymore.
Fridges, garage door openers, microwaves, light bulbs, clock radios, natural gas furnaces, and anything else that doesn't work with 240v: That stuff is dead in the water without converting back down to 120v using an autoformer or something.
Sure, we'll eventually get things updated; when we don't count survivorship bias examples, it's plain to see that stuff just doesn't last all that long anyway (and never actually did).
But for a time: There literal mountains of stuff that just won't work without help. And that's a tough pill to swallow.
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What we could start doing is embrace our existing dual-voltage home wiring methods, and putting 240v sockets in some places where it's actually beneficial. Places like kitchens (for heating water and food), say. But broadly speaking: Nobody does this because nobody sells safety-approved residential appliances for the US domestic market, so it's a lot of money to spend to get it done for no benefit. It's a catch-22.
> Alternatively you can just run everything at 230V
Sure and everyone can just stop using Python 2.x tomorrow right?
Backwards compatibility is a big deal. Even moreso when it involves physical infrastructure. who wants to pay billions upon billions of dollars to make the change? How long will it take to roll trucks on all those linemen and electricians to convert/retrofit everything? Does the customer pay? The government?
And at the end of it everything is just the same as it was before. There's no huge benefit to be had for doing it.
That's why I said I wished we had more use of the 240v NEMA plugs. So we could begin supporting higher power appliances over time without some huge switchover expense.
For that matter I wish 3-phase was more available. I have a small machine shop in my garage that would greatly benefit from it.
Zero. My office workstation has 48 GB of RAM, my home computer has 64 (I went a bit overboard). I have very bad memories of swap thrashing and the computer becoming totally unresponsive until I forced a reset; if I manage to fill up so much RAM, I very much prefer the offending process to die instead of killing the whole computer.
It's funny how people think they're disabling swapping just because they don't have a swap file. Where do you think mmap()-ed file pages go? Your machine can still reclaim resident file-backed pages (either by discarding them if they're clear or writing them to their backing file if dirty) and reload them later. That's.... swap.
Instead of achieving responsiveness by disabling swap entirely (which is silly, because everyone has some very cold pages that don't deserve to be stuck in memory), people should mlockall essential processes, adjust the kernel's VM swap propensity, and so on.
Also, I wish we'd just do away with the separation between the anonymous-memory and file-backed memory subsystems entirely. The only special about MAP_ANONYMOUS should be that its backing file is the swap file.
mmap is not swap. It's using the same virtual memory mechanisms to load/dump pages to disk. The policy for when to read and write those pages is completely different.
When the room for memory mapped files gets low enough you get bad thrashing anyway, so the policy difference isn't that important.
Having no swap limits how much you can overburden your computer, but you also hit problems earlier. Here's some example numbers for 64GB of memory: With swap you can go up to 62GB of active program data (85GB allocated and used) before you have performance issues. Without swap you can go up to 45GB of active program data (63GB allocated and used) before you hit a brick wall of either thrashing or killing processes. The no-swap version is better at maintaining snappiness within its happy range, but it's a tradeoff.
It is doing exactly what swap is doing. That it's swap with a different policy doesn't make it not-swap.
Also, that separate policy shouldn't even exist. For LRU/active-list/inactive-list purposes, why does it matter whether a page is anonymous or file-backed? If you need it, you need it, and if you don't, you don't. No reason for anonymous and file-backed memory to be separate sub-sub-systems under vm.
Anonymous memory and files have different access patterns. Files are frequently read sequentially and only once, so there is no need to keep them in memory. When files are read, cached memory pages are put into inactive file LRU first and promoted to active LRU only on the second access.
It is possible to unify things behind a single mechanism, yet apply different policies to different instances of this mechanism depending on circumstances and heuristics. We do not need almost entirely disjoint paging systems in the Linux kernel to notice that some kinds of memory have access patterns different from other kinds of memory. Instead of guessing based on whether someone used MAP_ANONYMOUS, we should observe what a program is actually doing.
All LRUs, file-backend and anonymous are handled by the same code. There are some conditionals here and there - executable pages are promoted to active LRU on the first access, locked pages (if I remember correctly) too, but all pages go through the same cycle. See this Linux Plumbers conference presentation https://www.youtube.com/watch?v=0bnWQF7WQP0 with the following slides https://d3s.mff.cuni.cz/files/teaching/nswi161/2023_24/08_li...
I'm not an expert, but aren't you just reducing the choice of what pages can be offloaded from RAM? Without swap space, only file-backed pages can be written out to reclaim RAM for other uses (including caching). With swap space, rarely used anonymous memory can be written out as well.
Swap space is not just for overcommitting memory (in fact, I suspect nowadays it rarely ever is), but also for improving performance by maximizing efficient usage of RAM.
With 48GB, you're probably fine, but run a few VMs or large programs, and you're backing your kernel into a corner in terms of making RAM available for efficient caching.
I have 64GB of RAM and 16GB of swap. Swap is small enough it can't get really out of hand.
I have memories from like 20 years ago that even when I had plenty of RAM, and plenty of it was free, I would get random OOM killer events relatively regularly. Adding just a tiny bit of swap made that stop happening.
I'm like 90% sure at this point it's just a stupid superstition I carry. But I'm not gonna stop doing it even though it is stupid.
Same here, though I settled on 32GB of swap because I have a 4TB SSD (caught a good sale on a Samsung EVO SSD at Newegg). But whenever I run `top`, I constantly see:
MiB Swap: 32768.0 total, 32768.0 free, 0.0 used.
I could safely get away with 4GB of swap, and see no difference.
Luckily we're not in the spinning HDDs thrashing a working set in and out of 128 MB of primary memory days anymore. We have laptops that ship with SSDs that read/write at 6 GB/s.
I was experimenting with some graphics algorithm and had a memory leak where it would leak the uncompressed 12 MP image with every iteration. I was browsing the web when waiting for it to process when I wondered why it was taking so long. That's when I noticed it was using 80+ GB of swap just holding onto all those dead frames. It finished and meanwhile it had no noticeable performance impact on whatever else I was doing.
I ran with a setup like this for a bit, but I experienced far worse thrashing (and far more sudden onset) than I did with swap enabled. You need to take some extra steps to get a quick and graceful failure on RAM exhaustion.
I did similar with my 32GB laptop, but it was fairly flaky for ~4 years and I just recently put 48GB of swap on and it's been so much better. It's using over 20GB of the swap. The are cases in Linux where running without swap results in situations very similar to swapping too much.
Oh god... My company uses Teams and it is one of the main reasons why I installed so much RAM on my workstation. Part of me wishes that the recent increase in RAM prices will force companies to reduce the ridiculous memory footprint of their software.
Do you actually use Japanese websites on frequently? Because I do live in Japan, and I hate their websites with a passion. Go use any Japanese online shop; the purchase flows are usually absurdly convoluted, and they are so information dense that sometimes you don't know what you are actually going to purchase. It is one of the reasons I rarely use Rakuten anymore...
Yeah, I hate to say it, but using Amazon.co.jp is SO refreshing after using a Japanese website. It's really unbelievable how bad most Japanese e-commerce sites are.
I recently restored my old GameCube. Back in the day I installed a ViperGC (the first modchip for the GameCube) to play "backups", but the optical drive has died.
But thanks to the community, after reflashing it with Gekkoboot it can load Swiss from a SP2SD2, and from there load ROMs from the SD card! Reflashing the modchip was a pain in the ass though, the programmer required a parallel port and the software only runs on Windows XP, but in the end it worked and I am pretty happy with the results.
The fan is a bit loud, but it seems to work correctly, so I don't plan to touch it.
However, the GC has a CR2032 battery to save the time and a few settings, and that battery was dead. But in Nintendo's infinite wisdom, the battery is soldered, not socketed, and the space around it is quite tight so a normal socket will not fit. Removing it and soldering a battery socket was quite a chore, I needed to try different models until I found one that fits, but in the end I managed to do it. When the new battery dies in 10~20 years it will be much easier to replace it.
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