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zznzz

HN member
Joined
Wed, Feb 15, 2023, 3:00 PM UTC
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30
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17 items

About zznzz

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Recent public activity

  1. comment
  2. comment
    Comment #35668088

    jax and whisper-jax support running on GPUs in addition to TPUs, this particular demo just runs on a TPU.

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    Comment #35164234

    what kind of lasers / lidar technology is this that is not reflected by trees?

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    Comment #35016955

    altra is also > 2 years old, so the age of the apple chip doesn’t matter Neoverse N1 is hardly a dog. It’s a decent enough core in a server processor that has 80 of them. Altra is …

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    Comment #34937959

    A comment on some of the presentation of the history (‘staunton has already noted the strangeness of bellyaching in 2021 about renormalization without mentioning the renormalizatio…

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    Comment #34849054

    What you describe (multiple cores sharing the same lock) sounds like true sharing, not false sharing. False sharing means cache line contention is when cores are using separate str…

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    Comment #34848014

    Accelerating Standard C++ with GPUs Using stdpar https://developer.nvidia.com/blog/accelerating-standard-c-wi...

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    Comment #34808281

    Yes, this only works for user space stacks, but that is sufficient since with ORC kernel stacks are solved (IMO) and it avoids all the issues with trying to mlock debuginfo of all …

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    Comment #34807403

    I don’t understand your concern - what about this would involve one process sniffing another process’s memory? The kernel would still be doing the unwinding, just not in the NMI ha…

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    Comment #34807375

    because this is about PMU based sampling, which involves triggering interrupts at some interval and doing the sampling while handling the interrupt

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    Comment #34807286

    It is not required to unwind the user space stack in the NMI handler. It can be done later before returning to user space in a context that can handle faults.

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    Comment #34807048

    See also https://lists.fedoraproject.org/archives/list/devel@lists.fe... - the botan phoronix results with frame pointers were probably measuring debug builds.

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    Comment #34805014

    I cannot comment on whether “everyone” is oblivious but yes, this is still the case - frame pointer based unwinding sometimes skips the caller when the IP is sampled before the cal…

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    Comment #34804954

    IIUC Windows implements in-kernel unwinding using FPO debug data embedded in every executable.

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    Comment #34804890

    Register renaming doesn’t significantly address the impact of reducing the number of architectural registers available to the compiler. With fewer register names available, the com…

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    Comment #34804826

    Can you give more detail? AFAIK frame pointers work fine for unwinding on aarch64. And on aarch64 the gcc default is not to omit frame pointers and IIRC when the default was switch…

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    Comment #34804742

    > Is DWARF unwinding so slow that that is actually faster? No. The only reason it works like this is because the upstream Linux kernel has thus far rejected in-kernel dwarf unwinde…