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Comment by jcalvinowens

10 hours ago

I'm really surprised to see you still hocking this.

We did extensive benchmarking of HHVM with and without your patches, and they were proven to make no statistically significant difference in high level metrics. So we dropped them out of the kernel, and they never went back in.

I don't doubt for a second you can come up with specific counterexamples and microbenchnarks which show benefit. But you were unable to show an advantage at the system level when challenged on it, and that's what matters.

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jcalvinowens

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adsharma  10 hours ago

You probably weren't there when servers were running for many days at a time.

By the time you joined and benchmarked these systems, the continuous rolling deployment had taken over. If you're restarting the server every few hours, of course the memory fragmentation isn't much of an issue.

> But you were unable to show an advantage at the system level when challenged on it, and that's what matters.

You mean 5 years after I stopped working on the kernel and the underlying system had changed?

I don't recall ever talking to you on the matter.

  • jcalvinowens  10 hours ago

    > By the time you joined and benchmarked these systems, the continuous rolling deployment had taken over

    Nope, I started in 2014.

    > I don't recall ever talking to you on the matter.

    I recall. You refused to believe the benchmark results and made me repeat the test, then stopped replying after I did :)

    • adsharma  10 hours ago

      The patches were written in 2011 and published in 2012. They did what they were supposed to at the time.

      For the peanut gallery: this is a manifestation of an internal eng culture at fb that I wasn't particularly fond of. Celebrating that "I killed X" and partying about it.

      You didn't reply to the main point: did you benchmark a server that was running several days at a time? Reasonable people can disagree about whether this a good deployment strategy or not. I tend to believe that there are many places which want to deploy servers and run for months if not days.

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