Module Name: src
Committed By: yamt
Date: Fri Apr 8 10:42:51 UTC 2011
Modified Files:
src/sys/uvm: uvm_fault.c
Log Message:
- ensure that the promoted page is on the queue even when later pmap_enter
failed.
- don't activate a page twice.
- remove an argument which is used only for an assertion.
- assertions and comments.
To generate a diff of this commit:
cvs rdiff -u -r1.182 -r1.183 src/sys/uvm/uvm_fault.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/uvm/uvm_fault.c
diff -u src/sys/uvm/uvm_fault.c:1.182 src/sys/uvm/uvm_fault.c:1.183
--- src/sys/uvm/uvm_fault.c:1.182 Thu Feb 10 21:05:52 2011
+++ src/sys/uvm/uvm_fault.c Fri Apr 8 10:42:51 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_fault.c,v 1.182 2011/02/10 21:05:52 skrll Exp $ */
+/* $NetBSD: uvm_fault.c,v 1.183 2011/04/08 10:42:51 yamt Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -32,7 +32,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.182 2011/02/10 21:05:52 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_fault.c,v 1.183 2011/04/08 10:42:51 yamt Exp $");
#include "opt_uvmhist.h"
@@ -536,6 +536,8 @@
* => if we fail (result != 0) we unlock everything.
* => on success, return a new locked anon via 'nanon'.
* (*nanon)->an_page will be a resident, locked, dirty page.
+ * => it's caller's responsibility to put the promoted nanon->an_page to the
+ * page queue.
*/
static int
@@ -756,8 +758,7 @@
static int uvm_fault_lower_enter(
struct uvm_faultinfo *, const struct uvm_faultctx *,
struct uvm_object *,
- struct vm_anon *, struct vm_page *,
- struct vm_page *);
+ struct vm_anon *, struct vm_page *);
static inline void uvm_fault_lower_done(
struct uvm_faultinfo *, const struct uvm_faultctx *,
struct uvm_object *, struct vm_page *);
@@ -797,7 +798,7 @@
ufi.orig_size = PAGE_SIZE; /* can't get any smaller than this */
error = ERESTART;
- while (error == ERESTART) {
+ while (error == ERESTART) { /* ReFault: */
anons = anons_store;
pages = pages_store;
@@ -1402,12 +1403,13 @@
pg = anon->an_page;
mutex_enter(&uvm_pageqlock);
- uvm_pageactivate(pg);
+ uvm_pageenqueue(pg); /* uvm_fault_upper_done will activate the page */
mutex_exit(&uvm_pageqlock);
pg->flags &= ~(PG_BUSY|PG_FAKE);
UVM_PAGE_OWN(pg, NULL);
/* deref: can not drop to zero here by defn! */
+ KASSERT(oanon->an_ref > 1);
oanon->an_ref--;
/*
@@ -1975,7 +1977,8 @@
}
KASSERT(pg == uobjpage);
- return uvm_fault_lower_enter(ufi, flt, uobj, NULL, pg, uobjpage);
+ KASSERT(uobj == NULL || (uobjpage->flags & PG_BUSY) != 0);
+ return uvm_fault_lower_enter(ufi, flt, uobj, NULL, pg);
}
/*
@@ -2118,18 +2121,20 @@
anon, pg, 0, 0);
}
- return uvm_fault_lower_enter(ufi, flt, uobj, anon, pg, uobjpage);
+ KASSERT(uobj == NULL || (uobjpage->flags & PG_BUSY) != 0);
+ return uvm_fault_lower_enter(ufi, flt, uobj, anon, pg);
}
/*
- * uvm_fault_lower_enter: enter h/w mapping of lower page.
+ * uvm_fault_lower_enter: enter h/w mapping of lower page or anon page promoted
+ * from the lower page.
*/
int
uvm_fault_lower_enter(
struct uvm_faultinfo *ufi, const struct uvm_faultctx *flt,
struct uvm_object *uobj,
- struct vm_anon *anon, struct vm_page *pg, struct vm_page *uobjpage)
+ struct vm_anon *anon, struct vm_page *pg)
{
struct vm_amap * const amap = ufi->entry->aref.ar_amap;
int error;
@@ -2137,14 +2142,13 @@
/*
* locked:
- * maps(read), amap(if !null), uobj(if !null), uobjpage(if uobj),
+ * maps(read), amap(if !null), uobj(if !null),
* anon(if !null), pg(if anon)
*
* note: pg is either the uobjpage or the new page in the new anon
*/
KASSERT(amap == NULL || mutex_owned(&amap->am_l));
KASSERT(uobj == NULL || mutex_owned(&uobj->vmobjlock));
- KASSERT(uobj == NULL || (uobjpage->flags & PG_BUSY) != 0);
KASSERT(anon == NULL || mutex_owned(&anon->an_lock));
KASSERT((pg->flags & PG_BUSY) != 0);
@@ -2173,6 +2177,15 @@
* as the map may change while we're asleep.
*/
+ /*
+ * ensure that the page is queued in the case that
+ * we just promoted the page.
+ */
+
+ mutex_enter(&uvm_pageqlock);
+ uvm_pageenqueue(pg);
+ mutex_exit(&uvm_pageqlock);
+
if (pg->flags & PG_WANTED)
wakeup(pg);
