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redo part of the last commit.

This commit is contained in:
chs 2002-01-01 22:18:39 +00:00
parent 18f7211eb9
commit a7ec5b4144
1 changed files with 13 additions and 11 deletions
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24
sys/uvm/uvm_fault.c
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@ -1,4 +1,4 @@
/* $NetBSD: uvm_fault.c,v 1.72 2001/12/31 22:34:39 chs Exp $ */
/* $NetBSD: uvm_fault.c,v 1.73 2002/01/01 22:18:39 chs Exp $ */
/*
*
@ -39,7 +39,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.72 2001/12/31 22:34:39 chs Exp $");
__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.73 2002/01/01 22:18:39 chs Exp $");
#include "opt_uvmhist.h"
@ -533,7 +533,7 @@ uvm_fault(orig_map, vaddr, fault_type, access_type)
{
struct uvm_faultinfo ufi;
vm_prot_t enter_prot, check_prot;
boolean_t wired, narrow, promote, locked, shadowed, wire_fault;
boolean_t wired, narrow, promote, locked, shadowed, wire_fault, cow_now;
int npages, nback, nforw, centeridx, error, lcv, gotpages;
vaddr_t startva, objaddr, currva, offset, uoff;
paddr_t pa;
@ -614,8 +614,12 @@ ReFault:
enter_prot = ufi.entry->protection;
wired = VM_MAPENT_ISWIRED(ufi.entry) || wire_fault;
if (wired)
if (wired) {
access_type = enter_prot; /* full access for wired */
cow_now = (check_prot & VM_PROT_WRITE) != 0;
} else {
cow_now = (access_type & VM_PROT_WRITE) != 0;
}
/*
* handle "needs_copy" case. if we need to copy the amap we will
@ -626,8 +630,7 @@ ReFault:
if (UVM_ET_ISNEEDSCOPY(ufi.entry)) {
KASSERT(fault_type != VM_FAULT_WIREMAX);
if ((access_type & VM_PROT_WRITE) ||
(ufi.entry->object.uvm_obj == NULL)) {
if (cow_now || (ufi.entry->object.uvm_obj == NULL)) {
/* need to clear */
UVMHIST_LOG(maphist,
" need to clear needs_copy and refault",0,0,0,0);
@ -1041,7 +1044,7 @@ ReFault:
if (anon->u.an_page->loan_count) {
if ((access_type & VM_PROT_WRITE) == 0) {
if (!cow_now) {
/*
* for read faults on loaned pages we just cap the
@ -1124,7 +1127,7 @@ ReFault:
* if we are out of anon VM we kill the process (XXX: could wait?).
*/
if ((access_type & VM_PROT_WRITE) != 0 && anon->an_ref > 1) {
if (cow_now && anon->an_ref > 1) {
UVMHIST_LOG(maphist, " case 1B: COW fault",0,0,0,0);
uvmexp.flt_acow++;
@ -1272,8 +1275,7 @@ Case2:
promote = TRUE; /* always need anon here */
} else {
KASSERT(uobjpage != PGO_DONTCARE);
promote = (access_type & VM_PROT_WRITE) &&
UVM_ET_ISCOPYONWRITE(ufi.entry);
promote = cow_now && UVM_ET_ISCOPYONWRITE(ufi.entry);
}
UVMHIST_LOG(maphist, " case 2 fault: promote=%d, zfill=%d",
promote, (uobj == NULL), 0,0);
@ -1427,7 +1429,7 @@ Case2:
*/
if (uobjpage->loan_count) {
if ((access_type & VM_PROT_WRITE) == 0) {
if (!cow_now) {
/* read fault: cap the protection at readonly */
/* cap! */
enter_prot = enter_prot & ~VM_PROT_WRITE;