My current theory is that the issue lies somewhere in the confluence of three things...

* libtorrent uses memory maps files
* I'm in the habit of using zram swap, for in-memory compressed swap, with the defaults, so up to 32Gb (pre-compression) can be stored here
* I recently switched from btrfs to ZFS, with the default 50% host memory ARC cache

I didn't see this behaviour before the switch to ZFS, so perhaps I need to tune some things here?

(2/2)

#linux #zfs

@stephen you can tune /sys/module/zfs/parameters/zfs_arc_shrinker_limit to control how quickly zfs frees memory from the ARC when Linux reports memory pressure. If you set it to 0 there is no limit.