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X-IronPort-AV: E=McAfee;i="6500,9779,10585"; a="387362054" X-IronPort-AV: E=Sophos;i="5.96,311,1665471600"; d="scan'208";a="387362054" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2023 08:30:46 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10585"; a="764361912" X-IronPort-AV: E=Sophos;i="5.96,311,1665471600"; d="scan'208";a="764361912" Received: from swapnadi-mobl2.amr.corp.intel.com (HELO [10.209.29.117]) ([10.209.29.117]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2023 08:30:44 -0800 Message-ID: Date: Mon, 9 Jan 2023 08:30:43 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [RFC PATCH 1/4] mcpage: add size/mask/shift definition for multiple consecutive page Content-Language: en-US To: Matthew Wilcox , Yin Fengwei Cc: linux-mm@kvack.org, akpm@linux-foundation.org, jack@suse.cz, hughd@google.com, kirill.shutemov@linux.intel.com, mhocko@suse.com, ak@linux.intel.com, aarcange@redhat.com, npiggin@gmail.com, mgorman@techsingularity.net, rppt@kernel.org, ying.huang@intel.com, tim.c.chen@intel.com References: <20230109072232.2398464-1-fengwei.yin@intel.com> <20230109072232.2398464-2-fengwei.yin@intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 0757F120002 X-Stat-Signature: aezfs635qgz6taz7qsnehzpkpricyorm X-HE-Tag: 1673281851-200973 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 1/9/23 05:24, Matthew Wilcox wrote: > On Mon, Jan 09, 2023 at 03:22:29PM +0800, Yin Fengwei wrote: >> The idea of the multiple consecutive page (abbr as "mcpage") is using >> collection of physical contiguous 4K page other than huge page for >> anonymous mapping. > This is what folios are for. You have an interesting demonstration > here that shows that moving to larger folios for anonymous memory > is worth doing (thank you!) but you're missing several of the advantages > of folios by going off and doing your own thing. It might not have come across in the changelog and cover letter, but Fengwei and the rest of us *totally* agree with you on this. "Doing your own thing" just isn't going to cut it and if this is going to go anywhere, it needs to use folios. This series is _pure_ RFC and the comments we're interested in is whether this demonstration warrants going back and doing it the right way (with folios).