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Tue, 14 May 2024 04:43:56 -0700 (PDT) MIME-Version: 1.0 From: Yiannis Nikolakopoulos Date: Tue, 14 May 2024 13:43:29 +0200 Message-ID: Subject: [Resend LSF/MM/BPF TOPIC] A case of a CXL compressed memory tier To: lsf-pc@lists.linux-foundation.org, Adam Manzanares Cc: "linux-mm@kvack.org" , "linux-cxl@vger.kernel.org" , Angelos Arelakis , "Weiny, Ira" , yiannis@zptcorp.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 79E78100016 X-Rspam-User: X-Rspamd-Server: rspam12 X-Stat-Signature: fc7t4yps1nn98p1adqq5hsjryrgqhca5 X-HE-Tag: 1715687037-98565 X-HE-Meta: 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 pk8f4juU aE+Xj8ZguxDScjyJQodlzLVM256DTAbD6DoBYeCCoM38iDEztqDue4uH0aa5pvSRN7gCcBq94DHDWoy2GqBsm7EFC8OPvVTCrl0yJdWmkgFLcF0czIzOTcjXhrp6SuFgy+fgpJHIVac3rXAZ8EY2yDYODWTNj8RsB5o9RE6oTt3mx6lkcSherfbIQ+DPZ75Dq51G247v99jZHDDFtDaro0CetqeyUhk0hg8UlrHohxZSKKLRRUd/jzl0BEa8FVfkLWRBM1q+Zdl2jNGtyrx1/TGNhzH1F8lssqDBAINjeBbJAFw5ZiZXyngLLnvWMy9xqwsL7jSB6kgk9tc1NViIBd+K9ZaE7KcWXbiF+zPYfYCrZCcBISvzxfxMsGeihNaB77XQ2 X-Bogosity: Ham, tests=bogofilter, spamicity=0.402867, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Resending this from my private email to make sure it conforms with the mailing list etiquette. Hello all, This is almost literally last minute and the work itself is only getting started. But since I'm virtually attending, I thought to give it a shot in case it is of interest. Background: at ZeroPoint Technologies we are developing inline memory compression IP. Currently we are focusing on CXL type 3 devices (memory expanders), effectively introducing a compressed memory tier (i.e. fulfilling the OCP specification "Hyperscale CXL Tiered Memory Expander Specification=E2=80=9D). To utilize the memory saved due to compression, we oversubscribe the Device Physical Address Space (DPA) in addition to some custom .io interfaces. If there is interest, I would be glad to present these APIs and how the host's point of view changes compared to a "typical" memory tiering system. The goal would be to get some early feedback and direction for our upstream driver development, before we start pushing the first RFCs. Best regards, Yiannis Nikolakopoulos