Re: [PATCH v1 04/11] mm/memremap: add ZONE_DEVICE support for compound pages

Jane Chu <[email protected]> Tue, 18 May 2021 12:56:18 -0700
Newsgroups org.01.lists.linux-nvdimm,org.kvack.linux-mm
Organization Oracle Corporation
Message-ID <[email protected]>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==