Marcelo Tosatti wrote:
Avoid mmap_sem / pt lock acquision if the pagetables are present. The
improvement for hugepage backed guests is more significant, since pte
walk + page grab for such mappings is serialized by mm->page_table_lock.
CC: Andrea Arcangeli <[EMAIL PROTECTED]>
I'd like to apply this. Andrea, can you verify that mmu notifiers
interaction is okay?
static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
+ struct page *page[1];
+ unsigned long addr;
+ int npages;
+ gfn_t gfn = vmf->pgoff;
struct kvm *kvm = vma->vm_file->private_data;
- struct page *page;
- if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
+ addr = gfn_to_hva(kvm, gfn);
+ if (kvm_is_error_hva(addr))
return VM_FAULT_SIGBUS;
- page = gfn_to_page(kvm, vmf->pgoff);
- if (is_error_page(page)) {
- kvm_release_page_clean(page);
+
+ npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
+ NULL);
+ if (unlikely(npages != 1))
return VM_FAULT_SIGBUS;
- }
- vmf->page = page;
+
+ vmf->page = page[0];
return 0;
}
Why this change?
--
error compiling committee.c: too many arguments to function
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