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No need to pass that around all over the place, I think > it can instead be computed by the single place that actually > consumes it. > Almost, but not quite. The problem is in the -EEXIST return code case for follow_page_mask(). In that case, we also need folio size (PMD, PUD, or normal) to be returned. The page_mask argument does that now, and as long as we are in C, it's awkward to do anything else. oh well. thanks, -- John Hubbard