choudanu4 · HackerTrans

hace 4 añosdiscuss

Can Wachy be used to trace kernel code as well? And would you need to do anything specific to get that to work? (How would Wachy find the kernel sources?)

I was thinking this would be pretty cool to use for debugging device drivers on embedded devices especially w.r.t latency.

choudanu4

hace 7 añosdiscuss

Since you seem to know, what company would one go to for fabricating a 500nm chip these days at that price?

choudanu4

hace 7 añosdiscuss

Does the PhantomData type in Rust do what you want? Or are you talking about something slightly different?

https://doc.rust-lang.org/nomicon/phantom-data.html

https://doc.rust-lang.org/std/marker/struct.PhantomData.html

So

  struct Sender<S> {
    /// Actual implementation of network I/O.
    inner: SenderImpl;  
    /// 0-sized field, doesn't exist at runtime.
    state: S;
  }

I believe could become

  struct Sender<S> {
    /// Actual implementation of network I/O.
    inner: SenderImpl;  
    /// 0-sized field, doesn't exist at runtime.
    _marker: PhantomData<S>;
  }

I've never used this PhantomData personally, so this might be wrong. Cheers!

choudanu4

hace 7 añosdiscuss

AMD’s primary advertised improvement here is the use of a TAGE predictor, although it is only used for non-L1 fetches. This might not sound too impressive: AMD is still using a hashed perceptron prefetch engine for L1 fetches, which is going to be as many fetches as possible, but the TAGE L2 branch predictor uses additional tagging to enable longer branch histories for better prediction pathways. This becomes more important for the L2 prefetches and beyond, with the hashed perceptron preferred for short prefetches in the L1 based on power.

I found this paragraph confusing, is it talking about data prefetchers (Which would make sense b/c of the mention of short prefetches) or branch predictors? (Which would make sense b/c of the mention of TAGE and Perceptron)

choudanu4

hace 8 añosdiscuss

Does anyone know where I could get more information on Tools?

choudanu4

hace 8 añosdiscuss

Yes, but for the previous few generations of transistor manufacturing, transistors' power consumption has not scaled down as well as their size. This is known as the failure of Dennard Scaling[0].

[0] https://en.wikipedia.org/wiki/Dennard_scaling

choudanu4

hace 8 añosdiscuss

But I was under the impression that Linux isn't suitable as a real-time operating system (RTOS)[1] (which Microsoft may very well not require for their IoT systems). So the Linux Foundation providing an alternative free kernel meeting RTOS requirements makes perfect sense.

I'm not as clear on the history, but was Linux ever pitched as capable of being real-time OS? I don't think so. The hard requirements for real-time generally lead to very different systems than general-purpose operating systems.

[1] https://en.wikipedia.org/wiki/Real-time_operating_system

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