spoiler

made you look

  • 0 Posts
  • 175 Comments
Joined 10 months ago
Cake day: July 27th, 2024
  • The_Decryptor@aussie.zonetoLobste.rs@lemmy.bestiver.se•Memory Safety Features in ZigEnglish
    1·
    4 days ago

    I don’t think a majority of these actually have anything to do with memory safety, stuff like bounds checking definitely does, but error handling via tagged unions?

    It’s also a bit confusing to have sections about how robust bounds checking is performed during compilation and at runtime, then a couple of points later show how you have to manually do bounds checking otherwise you can have undefined behaviour, since bounds checking isn’t performed when compiling for “fast” or “small” outputs.

  • The_Decryptor@aussie.zonetolinuxmemes@lemmy.world•This happened to me at least 3 times.English
    4·
    5 days ago

    From a quick search it seems that the mobo uses a Realtek audio chip, which is probably the actual problem. My current system build uses one and it barely worked under Windows, it’d randomly remap the channels, sometimes it just wouldn’t come up properly (Showed as only a microphone, etc.), had lots of static noise, would constantly think I was unplugging and replugging headphones in, etc. Just a terrible experience compared to the Intel audio system the build before this used.

    As much as “just buy another bit of hardware” is an awful bit of advice, I’d recommend getting a USB DAC/soundcard, I bought a cheap soundblaster one and it fixed all my problems. USB audio is a well-defined standardised protocol that’s supported by just about everything, does away with any driver issues or incompatibilities, can be moved between devices, etc. Mine’s a “gaming” model so it’s just a USB port on one side and a headset jack on the other, but you can also get ones with proper inbuilt amplifiers to run full speaker kits, etc.

  • The_Decryptor@aussie.zonetoLobste.rs@lemmy.bestiver.se•Don't make Google sell ChromeEnglish
    6·
    9 days ago

    Look, Google’s trillion-dollar business depends on a thriving web that can be searched by Google.com, that can be plastered in AdSense, and that now can feed the wisdom of AI. Thus, Google’s incredible work to further the web isn’t an act of charity, it’s of economic self-interest, and that’s why it works. Capitalism doesn’t run on benevolence, but incentives.

    My sarcasm sensor is fried these days, but I honestly can’t tell if this is supposed to be satire or not.

    I remember people making the same arguments as to why IE was the best browser and why their anti-trust suit wasn’t fair, didn’t make sense then and doesn’t now,

  • The_Decryptor@aussie.zonetomemes@lemmy.world•What would you do if you had 32GB RAM?English
    1·
    12 days ago

    So one of the problems is the size of a “physical page”, on a stock x86 system that’s only 4KiB. If you allocate just 1MiB of RAM you need to back that with 256 “page table entries”, and to then load a virtual address within that allocation you need to walk that list of 256 entries to find the physical address in RAM that the CPU needs to request.

    Of course these days an app is more likely to use 1 GiB of RAM, that’s a mere 262,144 page table entries to scan through, on each memory load.

    Oh but then we’re also not running a single process, there’s multiple processes on the system, so there will be several million of these entries, each one indexed by address (Which can be duplicated, each process has its own private view of the address space), and then by process ID to disambiguate which entry belongs to each process.

    That’s where the TLB comes in handy, to avoid the million or so indexing operations on each and every memory load.

    But caching alone can’t solve everything, you need a smarter way to perform bookkeeping than simply using a flat list for when you don’t have a cached result. So the OS breaks down those mappings into smaller chunks and then provides a table that maps address ranges to those chunks. An OS might cap a list of PTEs at 4096 and have another table index that, so to resolve an address the CPU checks which block of PTEs to load from the first table and then only has to scan the list it points to.

    Like this, this is a 2 level scheme that Intel CPUs used before the Pentium Pro (iirc), the top 10 bits of an address selected an entry in the “page directory”, the CPU loads that and uses the next 10 bits to select the group of PTEs from that list, following that link that it finds the actual PTEs that describe the mappings and then it can scan that list to find the specific matching entry that describes the physical address to load (And it then promptly caches the result to avoid doing that again)

    So yes, for a given page size and CPU you have a fixed number of walks regardless of where the address lives in memory, but we also have more memory now. And much like a hoarder, the more space we have to store things, the more things we do store, and the more disorganised it gets. And even if you do clear a spot, the next thing you want to store might not fit there and you end up storing it someplace else. If you end up bouncing around looking for things you end up thrashing the TLB, throwing out cached entries you still need so now need to perform the entire table walk again (Just to invariably throw that result away soon after).

    Basically, you need to defrag your RAM periodically so that the mappings don’t get too complex and slow things down (Same is true for SSDs btw, you still need to defrag them to clean up the filesystem metadata itself, just less often than HDDs). Meta have been working on improvements to how Linux handles all this stuff (page table layout and memory compaction) for a while because they were seeing some of their long-lived servers ending up spending about 20% of CPU time simply wasted on doing repetitive walks due to a highly fragmented address space.

  • The_Decryptor@aussie.zonetomemes@lemmy.world•What would you do if you had 32GB RAM?English
    5·
    12 days ago

    The RA in RAM stands for random access; there is no seeking necessary.

    Well there is, CPUs need to map virtual addresses to physical ones. And the more RAM you have the more management of that memory you need to do (e.g. modern Intel and AMD CPUs have 5 levels of indirection between a virtual and physical address)

    But it also caches those address mappings, as long as your TLB is happy, you’re happy. An alternative is to use larger page sizes (A page being the smallest amount of RAM you can address), the larger the page the less you need recurse into the page tables to actually find said page, but you also can end up wasting RAM if you’re not careful.

  • The_Decryptor@aussie.zonetoComic Strips@lemmy.world•The Military Entertainment Complex:English
    4·
    13 days ago

    This is what my comment was about. You can’t make social change with super powers. Super powers are a tool of physical force. I’m sure someone could write a great story about a super hero leading a violent and justified revolution, but you can’t possibly expect that to be a hallmark of the genre.

    One of the marvel movies has a line about how Stark Industries is now the world leader in clean energy thanks to his arc reactor, that would have a massive societal impact and upend existing power structures, but it’d also make for a pretty boring film.

    While there would be some people who’d watch RDJ sit in meetings for 2 hours making agreements, it wouldn’t be the same amount that’d watch him put on the suit and punch people into orbit.

    Edit: Actually, on the other hand in Secret Invasion

    spoiler

    the US president has the UK prime minster assassinated on live television

    And even in universe they seem to have glossed over that.