Date:   Tue, 11 Jan 2022 01:41:22 -0700
From:   Yu Zhao <yuzhao@google.com>
To:     Alexandre Frade <kernel@xanmod.org>,
        Brian Geffon <bgeffon@google.com>,
        Daniel Byrne <djbyrne@mtu.edu>,
        Holger =?iso-8859-1?Q?Hoffst=E4tte?= 
        <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>,
        Suleiman Souhlal <suleiman@google.com>
Cc:     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@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>
Subject: Re: [PATCH v6 0/9] Multigenerational LRU Framework
Message-ID: <Yd1Css8+jsspeZHh@google.com>
References: <20220104202227.2903605-1-yuzhao@google.com>
 <YdSuSHa/Vjl6bPkg@google.com>
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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

Also my gratitude to those who have helped test MGLRU:

   Daniel - researcher at Michigan Tech
            benchmarked memcached
   
   Holger - who has been testing/patching/contributing to various
            subsystems since ~2008
   
   Shuang - researcher at University of Rochester
            benchmarked fio and provided a report
   
   Sofia  - EDI https://www.edi.works
            benchmarked the top eight memory hogs and provided reports

Can you please provide your Tested-by tags? This will ensure the credit
for your contributions.

Thanks!