Re: [PATCH v5 4/4] mm: Introduce per-thpsize swapin control policy

[Barry Song]

On Tue, Jul 30, 2024 at 4:11 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> On Mon, Jul 29, 2024 at 04:52:30AM +0100, Matthew Wilcox wrote:
> > I strongly disagree.  Use the same sysctl as the other anonymous memory
> > allocations.
>
> I agree with Matthew here.

The whole anonymous memory allocation control is still used here. this is
just an addition: anonymous memory allocation control & swapin policy,
primarily for addressing SSD concern not for zRAM in the original v4's
comment.

>
> We also really need to stop optimizing for this weird zram case and move
> people to zswap instead after fixing the various issues.  A special
> block device that isn't really a block device and needs various special
> hooks isn't the right abstraction for different zwap strategies.

My understanding is zRAM is much more popularly used in embedded
systems than zswap. I seldomly(or never) hear who is using zswap
in Android. it seems pointless to force people to move to zswap, in
embedded systems we don't have a backend real block disk device
after zswap.

>