alt Hacker NewsI started wondering if there could be swap-aware GC, like first make the required page swapped in (not that there's any obvious API for that...) and only then pause the world?
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One can just add APIs to the Linux kernel, and this would be a pretty straightforward one. (though it might be a little more difficult to avoid a syscall here)
I'm sure an agent can work on this and get some numbers with a day's worth of tokens.
You could do lots of interesting things with sufficiently deep inter-layer integration.
For example, why not swap out not by LRU page but by dense node clusters on the heap graph, maintaining in-memory summaries of inbound and outbound edges for liveness? If you do this, you don't have to swap the cluster in to do a GC involving it.
If the whole cluster becomes unreachable, you wouldn't even have to swap it back in to get rid of it: you'd just drop the swap reference and deem the swap space free.
I don't see anything this deeply integrated happening near-term, but it's fun to think about.
Aren't madvise and mincore the APIs you want?