Re: [PATCH v6 0/9] Multigenerational LRU Framework

From: "Steven Barrett" <steven@liquorix.net>
To: "Yu Zhao" <yuzhao@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
Date: Wed, 19 Jan 2022 14:19:30 -0600	[thread overview]
Message-ID: <9203f79f-7910-4613-a593-aa6fda665b42@www.fastmail.com> (raw)
In-Reply-To: <Yd1Css8+jsspeZHh@google.com>

On Tue, Jan 11, 2022, at 2:41 AM, Yu Zhao 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
> 
> 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!

This feature has been a huge improvement for desktop linux, system
responsiveness has hit a new level high memory pressure.  Thanks Yu!

Acked-by: Steven Barrett <steven@liquorix.net>