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I don't like this a lot, > because it's two loads rather than one atomic load, but it should only > be present for one commit. > > In the next commit, we can separately allocate struct folio, make > page->memdesc point to struct folio and drop the PGTY_slab check (as > there will be no more uses of the first tail page for the mapcount stuff). So to rephrase, there is no great free space for memdesc in struct page right now, but after the folio is split then it is fine? Thus you have a few commits within a single series where it is less efficient? Seems OK to me.. Jason