Re: Path forward for Virtualized Swap?

[Rik van Riel <riel@surriel.com>]

On Tue, 2026-09-22 at 05:23 -1000, Chris Li wrote:
> 
> > > > > > Zswap:           8812236 kB
> > > > > > Zswapped:       24927876 kB
> 

> My original request was for the whole system: what percentage of the
> total system RAM size has been swapped out to zswap.
> 
24.9 GB out of 64 GB is 28%

That is how much application memory was swapped out to zswap.

12% is how much system memory is used by zswap.

Those are two very different things, and it really is not
clear to me which of the two you are talking about at what
point in time.


>  My observation is that, even with zswap, when 100% of
> system RAM is swapped out, the application suffers greatly. There is
> a
> reason why we only have 7-10% system RAM swapped out.

You mean for your specific workload, you do not
want more than 5-8 GB out of 64GB to be swapped
out?

That is perfectly acceptable. You should be able
to configure that.

However, your configuration values are not a good
default for my setup.

I believe we need to set the default to something
that accommodates a diverse range of desktop and
mobile users. 

Most of those users do not know what they will need, 
but they will know to close a few browser tabs when 
things get slow.

The companies running thousands of servers that
are carefully managed, and which overwhelmingly
have the same configuration values deployed to
them are more than capable of setting the dozen
or so config values their entire fleet might
need.

-- 
All Rights Reversed.