From d4f827eb7aac16e5c12a421026362bdcbdf6ac97 Mon Sep 17 00:00:00 2001 From: alc Date: Mon, 26 Oct 2009 00:01:52 +0000 Subject: Simplify the inner loop of vm_fault_copy_entry(). Reviewed by: kib --- sys/vm/vm_fault.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'sys/vm') diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c index 4314fda..508d617 100644 --- a/sys/vm/vm_fault.c +++ b/sys/vm/vm_fault.c @@ -1133,20 +1133,20 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map, { vm_object_t backing_object, dst_object, object; vm_object_t src_object; - vm_ooffset_t dst_offset; - vm_ooffset_t src_offset; - vm_pindex_t pindex; + vm_pindex_t dst_pindex, pindex, src_pindex; vm_prot_t prot; vm_offset_t vaddr; vm_page_t dst_m; vm_page_t src_m; + boolean_t src_readonly; #ifdef lint src_map++; #endif /* lint */ src_object = src_entry->object.vm_object; - src_offset = src_entry->offset; + src_pindex = OFF_TO_IDX(src_entry->offset); + src_readonly = (src_entry->protection & VM_PROT_WRITE) == 0; /* * Create the top-level object for the destination entry. (Doesn't @@ -1177,16 +1177,16 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map, * one from the source object (it should be there) to the destination * object. */ - for (vaddr = dst_entry->start, dst_offset = 0; + for (vaddr = dst_entry->start, dst_pindex = 0; vaddr < dst_entry->end; - vaddr += PAGE_SIZE, dst_offset += PAGE_SIZE) { + vaddr += PAGE_SIZE, dst_pindex++) { /* - * Allocate a page in the destination object + * Allocate a page in the destination object. */ do { - dst_m = vm_page_alloc(dst_object, - OFF_TO_IDX(dst_offset), VM_ALLOC_NORMAL); + dst_m = vm_page_alloc(dst_object, dst_pindex, + VM_ALLOC_NORMAL); if (dst_m == NULL) { VM_OBJECT_UNLOCK(dst_object); VM_WAIT; @@ -1201,10 +1201,9 @@ vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map, */ VM_OBJECT_LOCK(src_object); object = src_object; - pindex = 0; - while ((src_m = vm_page_lookup(object, pindex + - OFF_TO_IDX(dst_offset + src_offset))) == NULL && - (src_entry->protection & VM_PROT_WRITE) == 0 && + pindex = src_pindex + dst_pindex; + while ((src_m = vm_page_lookup(object, pindex)) == NULL && + src_readonly && (backing_object = object->backing_object) != NULL) { /* * Allow fallback to backing objects if we are reading. -- cgit v1.1