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References: <20220104202227.2903605-1-yuzhao@google.com> <YdSuSHa/Vjl6bPkg@google.com>
 <Yd1Css8+jsspeZHh@google.com>
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From:   Suleiman Souhlal <suleiman@google.com>
Date:   Wed, 12 Jan 2022 10:46:19 +0900
Message-ID: <CABCjUKBiECMEgnMaCrfApVbWPgw3UuwNH+-Y9ME+2ogJSm+p-Q@mail.gmail.com>
Subject: Re: [PATCH v6 0/9] Multigenerational LRU Framework
To:     Yu Zhao <yuzhao@google.com>
Cc:     Alexandre Frade <kernel@xanmod.org>,
        Brian Geffon <bgeffon@google.com>,
        Daniel Byrne <djbyrne@mtu.edu>,
        =?UTF-8?Q?Holger_Hoffst=C3=A4tte?= <holger@applied-asynchrony.com>,
        Jan Alexander Steffens <heftig@archlinux.org>,
        Shuang Zhai <szhai2@cs.rochester.edu>,
        Sofia Trinh <sofia.trinh@edi.works>,
        Steven Barrett <steven@liquorix.net>,
        Andi Kleen <ak@linux.intel.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Hillf Danton <hdanton@sina.com>, Jens Axboe <axboe@kernel.dk>,
        Jesse Barnes <jsbarnes@google.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Matthew Wilcox <willy@infradead.org>,
        Mel Gorman <mgorman@suse.de>,
        Michael Larabel <Michael@michaellarabel.com>,
        Michal Hocko <mhocko@kernel.org>,
        Rik van Riel <riel@surriel.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Will Deacon <will@kernel.org>,
        Ying Huang <ying.huang@intel.com>,
        linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        linux-mm@kvack.org, page-reclaim@google.com, x86@kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
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On Tue, Jan 11, 2022 at 5:41 PM Yu Zhao <yuzhao@google.com> wrote:
>
> On Tue, Jan 04, 2022 at 01:30:00PM -0700, Yu Zhao wrote:
> > On Tue, Jan 04, 2022 at 01:22:19PM -0700, Yu Zhao wrote:
> > > TLDR
> > > ====
> > > The current page reclaim is too expensive in terms of CPU usage and it
> > > often makes poor choices about what to evict. This patchset offers an
> > > alternative solution that is performant, versatile and
> > > straightforward.
> >
> > <snipped>
> >
> > > Summery
> > > =======
> > > The facts are:
> > > 1. The independent lab results and the real-world applications
> > >    indicate substantial improvements; there are no known regressions.
> > > 2. Thrashing prevention, working set estimation and proactive reclaim
> > >    work out of the box; there are no equivalent solutions.
> > > 3. There is a lot of new code; nobody has demonstrated smaller changes
> > >    with similar effects.
> > >
> > > Our options, accordingly, are:
> > > 1. Given the amount of evidence, the reported improvements will likely
> > >    materialize for a wide range of workloads.
> > > 2. Gauging the interest from the past discussions [14][15][16], the
> > >    new features will likely be put to use for both personal computers
> > >    and data centers.
> > > 3. Based on Google's track record, the new code will likely be well
> > >    maintained in the long term. It'd be more difficult if not
> > >    impossible to achieve similar effects on top of the existing
> > >    design.
> >
> > Hi Andrew, Linus,
> >
> > Can you please take a look at this patchset and let me know if it's
> > 5.17 material?
> >
> > My goal is to get it merged asap so that users can reap the benefits
> > and I can push the sequels. Please examine the data provided -- I
> > think the unprecedented coverage and the magnitude of the improvements
> > warrant a green light.
>
> Downstream kernel maintainers who have been carrying MGLRU for more than
> 3 versions, can you please provide your Acked-by tags?
>
> Having this patchset in the mainline will make your job easier :)
>
>    Alexandre - the XanMod Kernel maintainer
>                https://xanmod.org
>
>    Brian     - the Chrome OS kernel memory maintainer
>                https://www.chromium.org
>
>    Jan       - the Arch Linux Zen kernel maintainer
>                https://archlinux.org
>
>    Steven    - the Liquorix kernel maintainer
>                https://liquorix.net
>
>    Suleiman  - the ARCVM (Android downstream) kernel memory maintainer
>                https://chromium.googlesource.com/chromiumos/third_party/kernel

Android on ChromeOS has been using MGLRU for a while now, with great results.
It would be great for more people to more easily be able to benefit from it.

Acked-by: Suleiman Souhlal <suleiman@google.com>

-- Suleiman