[jbellis]

[article author]

TBH this was sloppy on my part. I tested multiple runs of the index build and early on kswapd was super busy. I assumed Linux was just caching recently read parts of the source dataset, but it's also possible it was something external to the index build since it's my daily driver machine. After I turned off swap I had no issues and didn't look into it harder.

[cwillu]

The usual thing would be to fadvise(POSIX_FADV_DONTNEED) the relevant file handle you don't want cached.

Edit: see for instance https://insights.oetiker.ch/linux/fadvise.html