Re: [PATCH v2] mm: add zblock allocator

[Igor Belousov]

> > >> >>> Do you have zswap/zswapped meminfo metrics from these tests?
> > >> >> Yep, and those look somewhat similar:
> > >> >>  - zblock:
> > >> >> Zswap:            234128 kB
> > >> >> Zswapped:         733216 kB
> > >> >> -  zsmalloc:
> > >> >> Zswap:            286080 kB
> > >> >> Zswapped:         774688 kB
> > >> >
> > >> > I tested the kernel build on a 4-core virtual machine with allocated 4
> > >> > GB RAM running on a Ryzen 9.
> > >> >
> > >> > The results are the following:
> > >> [...]
> > >>
> > >> Now what's funny is that when I tried to compare how 32 threaded build
> > >> would behave on a 8-core VM I couldn't do it because it OOMs with
> > >> zsmalloc as zswap backend. With zblock it doesn't, though, and the
> > >> results are:
> > >> real    12m14.012s
> > >> user    39m37.777s
> > >> sys     14m6.923s
> > >> Zswap:            440148 kB
> > >> Zswapped:         924452 kB
> > >> zswpin 594812
> > >> zswpout 2802454
> > >> zswpwb 10878
> > >>
> > >> /Igor
> > >
> > > May I ask what compression algorithm you are using?
> >
> > It's LZ4 for all the test runs.
>
> Can you try zstd and let me know how it goes :)

Sure. zstd/8 cores/make -j32:

zsmalloc:
real	7m36.413s
user	38m0.481s
sys	7m19.108s
Zswap:            211028 kB
Zswapped:         925904 kB
zswpin 397851
zswpout 1625707
zswpwb 5126

zblock:
real	7m55.009s
user	39m23.147s
sys	7m44.004s
Zswap:            253068 kB
Zswapped:         919956 kB
zswpin 456843
zswpout 2058963
zswpwb 3921

> > > And does the zswpwb come from zswap shrinker?
> >
> > Haven't looked into that, to be honest.
>
> Can you check:
>
> /sys/module/zswap/parameters/shrinker_enabled

It's 'Y' so the answer is yes.

/Igor