On Mon, Feb 10, 2020 at 06:12:39AM -0800, Brian Geffon wrote: > Hi Kirill, > If the old_len == new_len then there is no change in the number of > locked pages they just moved, if the new_len < old_len then the > process of unmapping (new_len - old_len) bytes from the old mapping > will handle the locked page accounting. So in this special case where > we're growing the VMA, vma_to_resize() will enforce that growing the > vma doesn't exceed RLIMIT_MEMLOCK, but vma_to_resize() doesn't handle > incrementing mm->locked_bytes which is why we have that special case > incrementing it here. But if you do the operation for the VM_LOCKED vma, you'll have two locked VMA's now, right? Where do you account the old locked vma you left behind? -- Kirill A. Shutemov
