[PATCH v3 07/20] mm: Cache some VMA fields in the vm_fault structure

2017-09-08 Thread Laurent Dufour
When handling speculative page fault, the vma->vm_flags and vma->vm_page_prot fields are read once the page table lock is released. So there is no more guarantee that these fields would not change in our back. They will be saved in the vm_fault structure before the VMA is checked for changes.

[PATCH v3 07/20] mm: Cache some VMA fields in the vm_fault structure

2017-09-08 Thread Laurent Dufour
When handling speculative page fault, the vma->vm_flags and vma->vm_page_prot fields are read once the page table lock is released. So there is no more guarantee that these fields would not change in our back. They will be saved in the vm_fault structure before the VMA is checked for changes.