For the peanut gallery more: I worked with both of these guys at Meta on this.

The "servers are only on for a few hours" thing was like never true so I have no idea where that claim is coming from. The web performance test took more than a few hours to run alone and we had way more aggressive soaks for other workloads.

My recollection was that "write zeroes" just became a cheaper operation between '12 and '14.

A fun fact to distract from the awkwardness: a lot of the kernel work done in the early days was exceedingly scrappy. The port mapping stuff for memcached UDP before SO_REUSEPORT for example. FB binaries couldn't even run on vanilla linux a lot of the time. Over the next several years we put a TON of effort in getting as close to mainline as possible and now Meta is one of the biggest drivers of Linux development.

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adsharma 2 hours ago | parent | next [-]

[ Edit: "servers" in this context meant the HHVM server processes, not the physical server which of course had a longer uptime ]

People got promoted for continuous deployment

https://engineering.fb.com/2017/08/31/web/rapid-release-at-m...

I think it's fair to say the hardware changed, the deployment strategy changed and the patches were no longer relevant, so we stopped applying them.

When I showed up, there were 100+ patches on top of a 2009 kernel tree. I reduced the size to about 10 or so critical patches, rebased them at a 6 months cadence over 2-3 years. Upstreamed a few.

Didn't go around saying those old patches were bad ideas and I got rid of them. How you say it matters.

	▲	alexgartrell 2 hours ago \| parent [-]
		The linked article says they decided to do CD in 2016 fwiw so that's not inconsistent with what I said. You reduced the number of patches a lot and also pushed very hard to get us to 3.0 after we sat on 2.6.38 ~forever. Which was very appreciated, btw. We built the whole plan going forward based on this work. I'm not arguing that anyone should be nice to anyone or not (it's a waste of breath when it comes to Linux). I'm just saying that the benchmarking was thorough and that contemporary 2014 hardware could zero pages fast.

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eduction 33 minutes ago | parent | prev [-]

I use Facebook and Instagram and think you all suck. Slagging each other in public. Grow tf up.