02-01-2020, 08:56 AM
(02-01-2020, 02:04 AM)Solra Bizna Wrote:Very possible - my total RAM usage ((zram content + used RAM - zram compressed size)/total RAM) was usually sitting in 160%-180% range, that is around 5GiB +/- (accounting for only a little over 3GiB accessible out of 4GiB). With that usage on zswap data was getting dumped onto disk and I wasn't getting much I/O savings, but I was still taking the CPU hit from constant compressing/decompressing I would be doing with zram anyway. To be fair though, there was some I/O hit with zram too - after all if RAM pressure gets too high the VFS cache would be dropped as well as other non-anonymous pages... I still have my trusty T60p around, maybe I'll try one of these weekends setting it up with default zswap parameters vs my zram setup and put it through its paces once more.(02-01-2020, 01:53 AM)moonwalkers Wrote: Would you mind sharing the specifics of how you tuned zswap? As well as your typical/max VM usage. Maybe you just figured out the right combination of tunables I couldn't, or maybe my SSD was no longer as fast as it used to be. But I was frequently cramming 5GiB of data in RAM on my TP T60p with zram, where zswap wasn't perceptibly much better than just plain swap.
Somehow I knew you would turn out to be a fellow T60p user...
I don't remember tuning it at all. I just set zswap.enabled=1, disabled my zram init script, and away I went. My [current] usage totals about 3.8 4.1GiB, including about 0.6GiB of buffer cache. Maybe your extra gibibyte makes all the difference. My T60p runs a very minimal Sawfish setup instead of a full DE, which helps a lot.