On Thu, Jul 15, 2021 at 06:28:42PM +0200, Helge Deller wrote: > On 7/15/21 3:46 PM, Matthew Wilcox (Oracle) wrote: > > These three architectures each define PMD_ORDER to mean "the order of > > an allocation for a PMD table", but logically PMD_ORDER should be the > > order of a PMD allocation, ie (PMD_SHIFT - PAGE_SHIFT) as DAX defines it. > > Some architectures do have PGD_ORDER, PUD_ORDER and PTE_ORDER as well. > If you rename PMD_ORDER, IMHO the others should be renamed too. > > Why not simply rename "PMD_ORDER" in fs/dax.c to e.g. > #define DAX_PMD_SHIFT (PMD_SHIFT - PAGE_SHIFT) > and use that inside the dax filesystem code? Because that's wrong. PMD order is clearly the order of a PMD page, not the order of a PMD table. I'm sure the others should also be renamed, but this is the one which is causing me pain today.