Re: Path forward for Virtualized Swap?

[Baoquan He <baoquan.he@linux.dev>]

On 09/24/26 at 09:20am, Klara Modin wrote:
> On 2026-09-24 13:51:50 +0800, Baoquan He wrote:
> > On 09/23/26 at 02:52pm, Klara Modin wrote:
> > > Hi,
> > > 
> ...
> > > 
> > > Chiming in as more of a user perspective.
> > > 
> > > On my 4 GiB BPI-F3, I can reach more than 10:1 compression ratio on
> > > zswap during some parts when building GCC 17 snapshots. E.g:
> > > 
> > > MemTotal:        3966864 kB
> > > SwapCached:        31872 kB
> > > SwapTotal:      16777212 kB
> > > SwapFree:       16638128 kB
> > > Zswap:            280140 kB
> > > Zswapped:        2859840 kB
> > > AnonPages:       2927376 kB
> > > AnonHugePages:   1409024 kB
> > > 
> > > While this is 72 % rather than the 100 % you asked for, I think this
> > > shows that what size a potential limit on the uncompressed size of zswap
> > > is suitable heavily depends on the workload.
> > > 
> > > I have been using vswap consistently on all my machines since about
> > > August, and I have also tried one or two versions of xswap (but the
> > > current lack of writeback makes it inconvenient for me). I really
> > 
> > Thanks for testing xswap and reporting issue on xswap rfc v3.
> > 
> > xswap has writeback now. I only built foundation for xswap, while
> > writeback part was left to other people for collaboration. Finally
> > I added it.
> > 
> > [RFC PATCH 00/17] mm, swap: xswap writeback to a physical backend
> > https://lore.kernel.org/all/20260920072043.430390-1-hebaoquan@kylinos.cn/T/#u
> > 
> 
> Thanks, I'll give it another try when I have time.

Sure, no hurry. Thanks a lot!