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Google fix for Meltdown & Specter - small impact, good fix

  1. Jan 12, 2018 #1

    jim mcnamara

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    Staff: Mentor

    This is the technical article:
    https://support.google.com/faqs/answer/7625886

    Please do not ask me for an executive summary. I fail Summary 101 repeatedly. Just ask my family.

    Google fixed the problems and has run extensive tests since September. They found little performance degradation for the 'Variant 2' attack prevention that everyone seems to complaining/worrying about. Their Retpoline change seems to work well. In other words the doomsayers just lost what they were moaning about. The fix is free, as in no cost. Unless you program and develop code you cannot really use it.

    You may see pop science articles about "Retpoline" - Return + Trampoline = "retpoline"
    A trampoline is an inline function (a self contained function inside another larger function) in computer code, the return(machine specific low-level) statement means end what you are doing immediately, and go back (return) to where you came from. Kind of like the Monopoly game's: "Go directly to jail, do not pass go".

    I cannot explain this any better for non-computer programmers, pop science articles may get it right accidentally. Someone else here can do better than I can.
     
  2. jcsd
  3. Jan 12, 2018 #2

    phyzguy

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    Science Advisor

    It sounds good. Can you explain what it means to us users? Can we expect an OS update that will fix the problem with no performance degradation? Any idea how long it will take to implement?
     
  4. Jan 12, 2018 #3

    jim mcnamara

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    Staff: Mentor

    Popular article: http://www.zdnet.com/article/google...ges-performance-hit-so-you-should-all-use-it/

    It means you have to wait for programs to be recompiled or patched, this includes the OS. Then you get it via Windows update, or for Linux via apt get, yum or whatever program your distribution uses to update software. The main impact is for cloud servers handling all those gigantic baby picture graphics files that people post and then store in the cloud. File I/O is the main point of performance impact for Variant 2 -- all the other proposed fixes - Microsoft & Intel included.

    All of us users now wait for a fix.
     
  5. Jan 14, 2018 #4
    It's disgusting. Compilers will need to be mutilated to generate that atrocity.
     
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