Re: Path forward for Virtualized Swap?

[Rik van Riel]

On Mon, 2026-09-21 at 08:10 -1000, Chris Li wrote:
> On Mon, Sep 21, 2026 at 6:40 AM Rik van Riel <riel@xxxxxxxxxxx>
> wrote:
> > 
> > On Mon, 2026-09-21 at 06:31 -1000, Chris Li wrote:
> > > 
> > > Give me some real-world examples of people hitting this kind of
> > > limit.
> > > e.g. MAX(%)  > 100% and still have a usesable system. I suspect
> > > that
> > > with 100% zswap usage, the system becomes unusable. Please show
> > > me a
> > > real world case that proves me wrong.
> > > 
> > 
> > Here's my desktop system right now. The amount
> > of Zswapped is more than twice AnonPages, and
> > the system stays perfectly usable.
> > 
> > $ grep -E '(Anon|Zswap|GPU|Swap)' /proc/meminfo
> > SwapCached:       252340 kB
> > SwapTotal:      41523604 kB
> > SwapFree:        9802088 kB
> > Zswap:           8812236 kB
> > Zswapped:       24927876 kB
> > AnonPages:      11615760 kB
> > AnonHugePages:   1402880 kB
> > GPUActive:      13112428 kB
> > GPUReclaim:        95980 kB
> > 
> > This is also an example where I cannot really
> > predict how much zswap space I need, because
> > that depends on what AI model is loaded,
> > which drives the GPUActive number, as well
> > as the number of browser tabs.
> > 
> > The system is perfectly responsive.
> 
> Great, that is getting somewhere. We are talking about actual usage.
> I
> really appreciate that.
> 
> May I ask what the total amount of memory (RAM) in your system is?
> 
> I am not asking zswap compare to ANA memory. I want to get the % of
> the total RAM.
> I assume your desktop has more than 8G of RAM, right?

Right now it has 64GB of memory.

However, if I were running with 48GB, I would
need MORE zswap space, while if I were running
with 96GB, I would need less zswap space.

How can people be expected to figure out how
much zswap space their system will need,
when the amount needed to fit a workload
does not have a positive correlation with
the amount of system memory?

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