RE: [PATCH v4 0/4] mm: ZSWAP swap-out of mTHP folios

["Sridhar, Kanchana P" <kanchana.p.sridhar@intel.com>]

> -----Original Message-----
> From: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> Sent: Tuesday, August 27, 2024 11:43 AM
> To: Nhat Pham <nphamcs@gmail.com>
> Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org;
> hannes@cmpxchg.org; yosryahmed@google.com; ryan.roberts@arm.com;
> Huang, Ying <ying.huang@intel.com>; 21cnbao@gmail.com; akpm@linux-
> foundation.org; Zou, Nanhai <nanhai.zou@intel.com>; Feghali, Wajdi K
> <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>;
> Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> Subject: RE: [PATCH v4 0/4] mm: ZSWAP swap-out of mTHP folios
> 
> 
> > -----Original Message-----
> > From: Nhat Pham <nphamcs@gmail.com>
> > Sent: Tuesday, August 27, 2024 8:30 AM
> > To: Sridhar, Kanchana P <kanchana.p.sridhar@intel.com>
> > Cc: linux-kernel@vger.kernel.org; linux-mm@kvack.org;
> > hannes@cmpxchg.org; yosryahmed@google.com; ryan.roberts@arm.com;
> > Huang, Ying <ying.huang@intel.com>; 21cnbao@gmail.com; akpm@linux-
> > foundation.org; Zou, Nanhai <nanhai.zou@intel.com>; Feghali, Wajdi K
> > <wajdi.k.feghali@intel.com>; Gopal, Vinodh <vinodh.gopal@intel.com>
> > Subject: Re: [PATCH v4 0/4] mm: ZSWAP swap-out of mTHP folios
> >
> > On Tue, Aug 27, 2024 at 8:23 AM Nhat Pham <nphamcs@gmail.com>
> wrote:
> > >
> > > On Mon, Aug 26, 2024 at 11:08 PM Sridhar, Kanchana P
> > > <kanchana.p.sridhar@intel.com> wrote:
> > > Yeah that's a bit unfair still. Wild idea, but what about we compare
> > > SSD without zswap (or SSD with zswap, but without this patch series so
> > > that mTHP are not zswapped) v.s zswap-on-zram (i.e with a backing
> > > swapfile on zram block device).
> > >
> > > It is stupid, I know. But let's take advantage of the fact that zram
> > > is not charged to cgroup, pretending that its memory foot print is
> > > empty?
> > >
> > > I don't know how zram works though, so my apologies if it's a stupid
> > > suggestion :)
> >
> > Oh nvm, looks like that's what you're already doing.
> >
> > That said, the lz4 column is soooo bad still, whereas the deflate-iaa
> > clearly shows improvement! This means it could be
> > compressor-dependent.
> >
> > Can you try it with zstd?
> 
> Sure, I will gather data with zstd.

I will be sending out a v5 shortly with data gathered with zstd.

Thanks,
Kanchana

> 
> Thanks,
> Kanchana