OK this is an old thread so may not be relevant any more.
SLES 12 can use “zswap” which is a compressed memory backed cache that sits between main ram and swap (e.g. it “goes through” this cache first).
In most cases, it can actually reduce the amount of I/O that eventually gets written to swap and in my limited testing has been beneficial.
It’s enabled by adding the “zswap.enabled=1” kernel parameter (Ysast2 bootloader &) and is listed as an option in the “official” SLES 12 release notes ( https://www.suse.com/releasenotes/x86_64/SUSE-SLES/12/ ).
I hope someone finds this useful.
Regards
Darren