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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon, 10 Jan 2022 17:41:58 -0800
Message-ID: <CAHk-=whAOM+xQm9vMe33qf8X1LX2QQZ7RBgKe_KH2C3LB=6Jdw@mail.gmail.com>
Subject: Re: [PATCH v6 0/9] Multigenerational LRU Framework
To:     Jesse Barnes <jsbarnes@google.com>
Cc:     Yu Zhao <yuzhao@google.com>, Michal Hocko <mhocko@suse.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        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>,
        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>,
        Rik van Riel <riel@surriel.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Will Deacon <will@kernel.org>,
        Ying Huang <ying.huang@intel.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>, page-reclaim@google.com,
        X86 ML <x86@kernel.org>
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On Mon, Jan 10, 2022 at 2:46 PM Jesse Barnes <jsbarnes@google.com> wrote:
>
> So unless we want to eschew big mm changes entirely (we shouldn't!
> look at net or scheduling for how important big rewrites are to
> progress), I think we should be open to experimenting with new stuff.

So I personally think this is worth going with, partly simply due to
the reported improvements that have been measured.

But also to a large extent because the whole notion of doing
multi-generational LRU isn't exactly some wackadoodle crazy thing. We
already do active vs inactive, the whole multi-generational thing just
doesn't seem to be so "far out".

 But yes, numbers talk, and I get the feeling that we just need to try
it. Maybe not 5.17, but..

           Linus