[RFC] zswap plugin

[TheHillBright]

zswap is an important feature to improve system performance. It has a few tunable parameters like zpool. Currently, tuned can handle them via sysfs plugin. But, if we think this is a frequently tuning parameter, it's preferable to have it own plugin and potentially setting sensible default in the existing profiles like what's done for vm.

[yarda]

Maybe we could add the 'swap' plugin for higher abstraction of swap related features and for the zswap specific options use the 'zswap_' prefix'.

[TheHillBright]

Interesting. I don't know what're other swap-related features besides zram (yes, tuned should support zram as well). One possibility is to have tuned manage swap mounts, but I wonder if this is bit unrelated to what tuned should do. From high-level point of view, swap has big impact on performance, so tuned should do something about it.