Re: [PATCH RFC] mm: count zeromap read and set for swapout and swapin

[Nhat Pham]

On Mon, Oct 28, 2024 at 5:23 AM Usama Arif <usamaarif642@xxxxxxxxx> wrote:
>
> I wonder if instead of having counters, it might be better to keep track
> of the number of zeropages currently stored in zeromap, similar to how
> zswap_same_filled_pages did it. It will be more complicated then this
> patch, but would give more insight of the current state of the system.
>
> Joshua (in CC) was going to have a look at that.

I don't think one can substitute for the other.

The "current zeromapped page" counter gives you a breakdown of where
memory resides, whereas the in/out counters explain past performance
based on events that have happened. That's why you have zswap,
zswapped, zswpout, zswpin.