Re: [PATCHv4 0/9] zsmalloc/zram: configurable zspage size

From: Sergey Senozhatsky
Date: Mon Nov 14 2022 - 03:37:53 EST


On (22/11/11 09:03), Minchan Kim wrote:
[..]
> for class in classes:
> wasted_bytes += class->pages_per_zspage * PAGE_SIZE - an object size
>
> with *aggressive zpage compaction*. Now, we are relying on shrinker
> (it might be already enough) to trigger but we could change the policy
> wasted memory in the class size crossed a threshold

That threshold can be another tunable in zramX/allocator_tunables sysfs
knob and struct zs_tunables.

But overall it sounds like a bigger project for some time next year.
We already have zs_compact() sysfs knob, so user-space can invoke it
as often as it wants to (not aware if anyone does btw), maybe new
compaction should be something slightly different. I don't have any
ideas yet. One way or the other it still can use the same sysfs knob :)