mm page_fault: Reduce code complexity

From: YangHui <[email protected]>

if pte_alloc_one fail alloc a page, do_fault_around will return 0. and in do_read_fault()->__do_fault(), it also pte_alloc_one a page. if pte_alloc_one failed to alloc a page,it will return VM_FAULT_OOM. To reduce code complexity,if alloc failed we return VM_FAULT_OOM.

---
 mm/memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index f703fe8..b104879 100644
@@ -3800,7 +3800,7 @@ static vm_fault_t do_fault_around(struct vm_fault *vmf)
 	if (pmd_none(*vmf->pmd)) {
 		vmf->prealloc_pte = pte_alloc_one(vmf->vma->vm_mm);
 		if (!vmf->prealloc_pte)
-			goto out;
+			return VM_FAULT_OOM;
 		smp_wmb(); /* See comment in __pte_alloc() */
 	}
 

2.7.4

This doesn't reduce code complexity at all. You've made this error different from every other error handled by this function because now it returns directly instead of jumping to 'out:'. I can't understand your explanation, and at first glance I'm not even sure this patch is correct. Definitely not a simplification, so NAK with this justification. The patch might be correct, but it'll need a lot better prose than this.