On 3/18/26 16:50, Lorenzo Stoakes (Oracle) wrote: > vma_flags_count() determines how many bits are set in VMA flags, using > bitmap_weight(). > > vma_flags_test_single_mask() determines if a vma_flags_t set of flags > contains a single flag specified as another vma_flags_t value, or if the > sought flag mask is empty, it is defined to return false. > > This is useful when we want to declare a VMA flag as optionally a single > flag in a mask or empty depending on kernel configuration. > > This allows us to have VM_NONE-like semantics when checking whether the > flag is set. > > In a subsequent patch, we introduce the use of VMA_DROPPABLE of type > vma_flags_t using precisely these semantics. > > It would be actively confusing to use vma_flags_test_any_single_mask() for > this (and vma_flags_test_all_mask() is not correct to use here, as it > trivially returns true when tested against an empty vma flags mask). > > We introduce vma_flags_count() to be able to assert that the compared flag > mask is singular or empty, checked when CONFIG_DEBUG_VM is enabled. > > Also update the VMA tests as part of this change. > > Signed-off-by: Lorenzo Stoakes (Oracle) <[email protected]>
Acked-by: Vlastimil Babka (SUSE) <[email protected]>
