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Transparent memory offloading: more memory at a fraction of the cost and power

engineering.fb.com

51–60 of 62 posts

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#51

Earlier quoted context omitted.

Funny. At first I laughed and the googled [0]. The response would suggest that either chinese teens are immune or china is blocking it in most of china. Or something else, but we know that the users are not in china. 0: https://www.statista.com/statistics/1299807/number-of-monthl...

I mean… why would they be on TikTok? China has its own clone (named Douyin) as they usually do. AFAIK it's very popular there.

[deleted]

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#52
post #37

Earlier quoted context omitted.

Oh absolutely. They copied what Facebook did and turned it up to 11. Their CCP ties give TikTok its own evil spin. The Chinese basically planted a mental health bomb among American teenagers. That doesn’t make Facebook the good guy though. In fact, they made it ridiculously easy for TikTok to come up with an even more addictive product.

Are Chinese teens immune to it?

Thats not the point. China controls it much more so that they have to make the algo addictive different.

Instead of promoting sex, they need to show helpfull videos (in theory)

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#53
post #30
post #20

If you are interested in Pressure Stall Information mentioned in the post, be sure to check LWN article on it, Tracking pressure-stall information: https://lwn.net/Articles/759781/

This was added in back 2018, so we've had a while to start using it.. anyone have experiences of other tools using this information?

We added it to the Prometheus node_exporter ages ago. It's extremely useful in detecting system stalls.

What I really need now is to have this information at the container level in cgroups v2.

https://github.com/google/cadvisor/issues/3052

This metric will really help with measuring the impact of workload CPU bursting.

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#54
post #35

I'm confused. They invented a swap partition?

The interesting bit (to me) is the algorithm. They automatically detect how slow each available swap space is, and how sensitive a workload is to memory latency and then swap memory pages into compressed dram or nvme storage in an optimal way.

So yes, it's "just swap space" but highly optimized.

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#55

The inevitable, albeit cynic response: Imagine how much DRAM could be saved if Facebook was shut down! Or put differently: I have only the greatest respect for the Facebook engineers who come up with innovations like this. This one seems to save cost, lowers power use and improves performance all at the same time. If only this engineering talent could be steered to better causes. Facebook is a net negative for societ…

>Facebook is a net negative for society Bold claim, Cotton. I personally have a hard time imagining a world where if Facebook didn't exist, something like it wouldn't either. There were plenty of companies vying for the same idea. Or is the suggestion that all usage of the internet to allow people to connect with each other are bad.

You need only imagine the year 2005.

Before newsfeeds and like buttons, the combo which enables Facebook's algorithmic hate machine (recommender to maximize engagement).

https://en.wikipedia.org/wiki/Feed_(Facebook) [2006]

https://en.wikipedia.org/wiki/Facebook_like_button [2009]

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#56
post #48
post #35

I'm confused. They invented a swap partition?

It seems kind of, but better because memory can be compressed and/or paged out using a more advanced algorithm than before which assumes fast NVME's available to inform it's decisions.

Compressed swap has also been around for ages.

There's also been swapping to GPU memory (if free).

There are also advanced page replacement algorithms.

One interesting algorithm I read about a while back was using LZW not to compress swap, but to predict future page usage from past patterns.

etc. etc.

It's all still paging/swapping.

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#57
post #4
post #3

or "Meta re-invents swap disk"

You should read the whole article, because TMO does differ from traditional swapping. Notably, swapping usually occurs during periods of extreme memory pressure, where as TMO will offload memory much sooner and more intelligently.

Nope.

Paging algorithms have been "pre-swapping" for ages in order to keep the free page reserve high (or preferably a purgeable page reserve).

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#58
post #14
post #3

or "Meta re-invents swap disk"

Ahhh, but they compress the memory! Anyone else remember Ram Doubler for pre OSX Macs?

IBM once had a main-memory interface that did LZW compression (so compressing between L2 and main memory).

Re: Transparent memory offloading: more memory at a fraction of the cost and power

#60
post #46
post #45

Earlier quoted context omitted.

“see what their friends and family are up to” isn’t actually connecting with people. I can see what some people are up to by watching reality TV, but that’s not connecting with them.

How about you let people connect how they want to, and you connect how you want to? You don’t need to tell us if these billions of people are living up to your standards. They just need to live up to theirs.

Wanting doesn’t make it so.

The issue is Facebook is built on people wanting to connect with others and Facebook is actively preventing this. Lonely people simply make better customers.

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