Could this be a reflection of the increasing gulf between RAM speed and HD speed? Even with NVMe drives, which one probably shouldn't be swapping to anyway, RAM is orders of magnitude faster.
Default settings for dirty ratio and dirty background ratio exacerbate the issue: more data is held onto before it is written, and once the background ratio is hit, any application writing to disk will block.
EDIT: see comment below for more accurate numbers.
>A typical reference to RAM is in the area of 100ns, accessing data on a SSD 150μs (so 1500 times of the RAM) and accessing data on a rotating disk 10ms (so 100.000 times the RAM.
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