1 files changed, 49 insertions, 186 deletions

diff --git a/sys/uvm/uvm_aobj.c b/sys/uvm/uvm_aobj.c
index 1bcc615fadc..cc5a075e77f 100644
--- a/sys/uvm/uvm_aobj.c
+++ b/sys/uvm/uvm_aobj.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_aobj.c,v 1.45 2009/06/16 23:54:57 oga Exp $	*/
+/*	$OpenBSD: uvm_aobj.c,v 1.46 2009/07/22 21:05:37 oga Exp $	*/
 /*	$NetBSD: uvm_aobj.c,v 1.39 2001/02/18 21:19:08 chs Exp $	*/
 
 /*
@@ -139,7 +139,7 @@ struct pool uao_swhash_elt_pool;
  * uvm_aobj: the actual anon-backed uvm_object
  *
  * => the uvm_object is at the top of the structure, this allows
- *   (struct uvm_device *) == (struct uvm_object *)
+ *   (struct uvm_aobj *) == (struct uvm_object *)
  * => only one of u_swslots and u_swhash is used in any given aobj
  */
 
@@ -176,8 +176,6 @@ static void			 uao_free(struct uvm_aobj *);
 static int			 uao_get(struct uvm_object *, voff_t,
 				     vm_page_t *, int *, int, vm_prot_t,
 				     int, int);
-static boolean_t		 uao_releasepg(struct vm_page *,
-				     struct vm_page **);
 static boolean_t		 uao_pagein(struct uvm_aobj *, int, int);
 static boolean_t		 uao_pagein_page(struct uvm_aobj *, int);
 
@@ -194,10 +192,6 @@ struct uvm_pagerops aobj_pager = {
 	NULL,			/* fault */
 	uao_flush,		/* flush */
 	uao_get,		/* get */
-	NULL,			/* put (done by pagedaemon) */
-	NULL,			/* cluster */
-	NULL,			/* mk_pcluster */
-	uao_releasepg		/* releasepg */
 };
 
 /*
@@ -565,7 +559,7 @@ uao_init(void)
 	simple_lock_init(&uao_list_lock);
 
 	/*
-	 * NOTE: Pages fror this pool must not come from a pageable
+	 * NOTE: Pages for this pool must not come from a pageable
 	 * kernel map!
 	 */
 	pool_init(&uao_swhash_elt_pool, sizeof(struct uao_swhash_elt),
@@ -641,8 +635,7 @@ void
 uao_detach_locked(struct uvm_object *uobj)
 {
 	struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
-	struct vm_page *pg, *next;
-	boolean_t busybody;
+	struct vm_page *pg;
 	UVMHIST_FUNC("uao_detach"); UVMHIST_CALLED(maphist);
 
 	/*
@@ -669,35 +662,26 @@ uao_detach_locked(struct uvm_object *uobj)
 	simple_unlock(&uao_list_lock);
 
 	/*
- 	 * free all the pages that aren't PG_BUSY,
-	 * mark for release any that are.
+	 * Free all pages left in the object. If they're busy, wait
+	 * for them to become available before we kill it.
+	 * Release swap resources then free the page.
  	 */
-	busybody = FALSE;
-	for (pg = TAILQ_FIRST(&uobj->memq); pg != NULL; pg = next) {
-		next = TAILQ_NEXT(pg, listq);
+	uvm_lock_pageq();
+	while((pg = TAILQ_FIRST(&uobj->memq)) != NULL) {
 		if (pg->pg_flags & PG_BUSY) {
-			atomic_setbits_int(&pg->pg_flags, PG_RELEASED);
-			busybody = TRUE;
+			atomic_setbits_int(&pg->pg_flags, PG_WANTED);
+			uvm_unlock_pageq();
+			UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
+			    "uao_det", 0);
+			simple_lock(&uobj->vmobjlock);
+			uvm_lock_pageq();
 			continue;
 		}
-
-		/* zap the mappings, free the swap slot, free the page */
 		pmap_page_protect(pg, VM_PROT_NONE);
 		uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
-		uvm_lock_pageq();
 		uvm_pagefree(pg);
-		uvm_unlock_pageq();
-	}
-
-	/*
- 	 * if we found any busy pages, we're done for now.
- 	 * mark the aobj for death, releasepg will finish up for us.
- 	 */
-	if (busybody) {
-		aobj->u_flags |= UAO_FLAG_KILLME;
-		simple_unlock(&aobj->u_obj.vmobjlock);
-		return;
 	}
+	uvm_unlock_pageq();
 
 	/*
  	 * finally, free the rest.
@@ -729,35 +713,6 @@ uao_detach_locked(struct uvm_object *uobj)
  * => we return TRUE unless we encountered some sort of I/O error
  *	XXXJRT currently never happens, as we never directly initiate
  *	XXXJRT I/O
- *
- * comment on "cleaning" object and PG_BUSY pages:
- *	this routine is holding the lock on the object.  the only time
- *	that is can run into a PG_BUSY page that it does not own is if
- *	some other process has started I/O on the page (e.g. either
- *	a pagein or a pageout).  if the PG_BUSY page is being paged
- *	in, then it can not be dirty (!PG_CLEAN) because no one has
- *	had a change to modify it yet.  if the PG_BUSY page is being
- *	paged out then it means that someone else has already started
- *	cleaning the page for us (how nice!).  in this case, if we
- *	have syncio specified, then after we make our pass through the
- *	object we need to wait for the other PG_BUSY pages to clear
- *	off (i.e. we need to do an iosync).  also note that once a
- *	page is PG_BUSY is must stary in its object until it is un-busyed.
- *	XXXJRT We never actually do this, as we are "flushing" anonymous
- *	XXXJRT memory, which doesn't have persistent backing store.
- *
- * note on page traversal:
- *	we can traverse the pages in an object either by going down the
- *	linked list in "uobj->memq", or we can go over the address range
- *	by page doing hash table lookups for each address.  depending
- *	on how many pages are in the object it may be cheaper to do one
- *	or the other.  we set "by_list" to true if we are using memq.
- *	if the cost of a hash lookup was equal to the cost of the list
- *	traversal we could compare the number of pages in the start->stop
- *	range to the total number of pages in the object.  however, it
- *	seems that a hash table lookup is more expensive than the linked
- *	list traversal, so we multiply the number of pages in the
- *	start->stop range by a penalty which we define below.
  */
 
 #define	UAO_HASH_PENALTY 4	/* XXX: a guess */
@@ -766,19 +721,13 @@ boolean_t
 uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 {
 	struct uvm_aobj *aobj = (struct uvm_aobj *) uobj;
-	struct vm_page *pp, *ppnext;
-	boolean_t retval, by_list;
+	struct vm_page *pp;
 	voff_t curoff;
 	UVMHIST_FUNC("uao_flush"); UVMHIST_CALLED(maphist);
 
-	curoff = 0;	/* XXX: shut up gcc */
-
-	retval = TRUE;	/* default to success */
-
 	if (flags & PGO_ALLPAGES) {
 		start = 0;
 		stop = aobj->u_pages << PAGE_SHIFT;
-		by_list = TRUE;		/* always go by the list */
 	} else {
 		start = trunc_page(start);
 		stop = round_page(stop);
@@ -787,13 +736,10 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 			    "flush (fixed)\n");
 			stop = aobj->u_pages << PAGE_SHIFT;
 		}
-		by_list = (uobj->uo_npages <=
-		    ((stop - start) >> PAGE_SHIFT) * UAO_HASH_PENALTY);
 	}
 
-	UVMHIST_LOG(maphist,
-	    " flush start=0x%lx, stop=0x%lx, by_list=%ld, flags=0x%lx",
-	    (u_long)start, (u_long)stop, by_list, flags);
+	UVMHIST_LOG(maphist, " flush start=0x%lx, stop=0x%lx, flags=0x%lx",
+	    (u_long)start, (u_long)stop, flags, 0);
 
 	/*
 	 * Don't need to do any work here if we're not freeing
@@ -802,44 +748,31 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 	if ((flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) {
 		UVMHIST_LOG(maphist,
 		    "<- done (no work to do)",0,0,0,0);
-		return (retval);
+		return (TRUE);
 	}
 
-	/*
-	 * now do it.  note: we must update ppnext in the body of loop or we
-	 * will get stuck.  we need to use ppnext because we may free "pp"
-	 * before doing the next loop.
-	 */
-
-	if (by_list) {
-		pp = TAILQ_FIRST(&uobj->memq);
-	} else {
-		curoff = start;
-		pp = uvm_pagelookup(uobj, curoff);
-	}
-
-	ppnext = NULL;	/* XXX: shut up gcc */
-	uvm_lock_pageq();	/* page queues locked */
-
-	/* locked: both page queues and uobj */
-	for ( ; (by_list && pp != NULL) ||
-	    (!by_list && curoff < stop) ; pp = ppnext) {
-		if (by_list) {
-			ppnext = TAILQ_NEXT(pp, listq);
-
-			/* range check */
-			if (pp->offset < start || pp->offset >= stop)
-				continue;
-		} else {
+	/* locked: uobj */
+	curoff = start;
+	for (;;) {
+		if (curoff < stop) {
+			pp = uvm_pagelookup(uobj, curoff);
 			curoff += PAGE_SIZE;
-			if (curoff < stop)
-				ppnext = uvm_pagelookup(uobj, curoff);
-
-			/* null check */
 			if (pp == NULL)
 				continue;
+		} else {
+			break;
 		}
-		
+
+		/* Make sure page is unbusy, else wait for it. */
+		if (pp->pg_flags & PG_BUSY) {
+			atomic_setbits_int(&pp->pg_flags, PG_WANTED);
+			UVM_UNLOCK_AND_WAIT(pp, &uobj->vmobjlock, 0,
+			    "uaoflsh", 0);
+			simple_lock(&uobj->vmobjlock);
+			curoff -= PAGE_SIZE;
+			continue;
+		}
+
 		switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
 		/*
 		 * XXX In these first 3 cases, we always just
@@ -848,7 +781,9 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 		 * XXX in the future.
 		 */
 		case PGO_CLEANIT|PGO_FREE:
+			/* FALLTHROUGH */
 		case PGO_CLEANIT|PGO_DEACTIVATE:
+			/* FALLTHROUGH */
 		case PGO_DEACTIVATE:
  deactivate_it:
 			/* skip the page if it's loaned or wired */
@@ -856,16 +791,13 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 			    pp->wire_count != 0)
 				continue;
 
-#ifdef UBC
-			/* ...and deactivate the page. */
-			pmap_clear_reference(pp);
-#else
+			uvm_lock_pageq();
 			/* zap all mappings for the page. */
 			pmap_page_protect(pp, VM_PROT_NONE);
 
 			/* ...and deactivate the page. */
-#endif
 			uvm_pagedeactivate(pp);
+			uvm_unlock_pageq();
 
 			continue;
 
@@ -882,19 +814,13 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 			    pp->wire_count != 0)
 				continue;
 
-			/*
-			 * mark the page as released if its busy.
-			 */
-			if (pp->pg_flags & PG_BUSY) {
-				atomic_setbits_int(&pp->pg_flags, PG_RELEASED);
-				continue;
-			}
-
 			/* zap all mappings for the page. */
 			pmap_page_protect(pp, VM_PROT_NONE);
 
 			uao_dropswap(uobj, pp->offset >> PAGE_SHIFT);
+			uvm_lock_pageq();
 			uvm_pagefree(pp);
+			uvm_unlock_pageq();
 
 			continue;
 
@@ -903,11 +829,9 @@ uao_flush(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
 		}
 	}
 
-	uvm_unlock_pageq();
-
 	UVMHIST_LOG(maphist,
 	    "<- done, rv=%ld",retval,0,0,0);
-	return (retval);
+	return (TRUE);
 }
 
 /*
@@ -989,10 +913,10 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 			}
 
 			/*
-			 * to be useful must get a non-busy, non-released page
+			 * to be useful must get a non-busy page
 			 */
 			if (ptmp == NULL ||
-			    (ptmp->pg_flags & (PG_BUSY|PG_RELEASED)) != 0) {
+			    (ptmp->pg_flags & PG_BUSY) != 0) {
 				if (lcv == centeridx ||
 				    (flags & PGO_ALLPAGES) != 0)
 					/* need to do a wait or I/O! */
@@ -1099,7 +1023,7 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 			}
 
 			/* page is there, see if we need to wait on it */
-			if ((ptmp->pg_flags & (PG_BUSY|PG_RELEASED)) != 0) {
+			if ((ptmp->pg_flags & PG_BUSY) != 0) {
 				atomic_setbits_int(&ptmp->pg_flags, PG_WANTED);
 				UVMHIST_LOG(pdhist,
 				    "sleeping, ptmp->flags 0x%lx\n",
@@ -1138,8 +1062,7 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 		/*
  		 * just zero the page if there's nothing in swap.
  		 */
-		if (swslot == 0)
-		{
+		if (swslot == 0) {
 			/*
 			 * page hasn't existed before, just zero it.
 			 */
@@ -1216,65 +1139,6 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 }
 
 /*
- * uao_releasepg: handle released page in an aobj
- * 
- * => "pg" is a PG_BUSY [caller owns it], PG_RELEASED page that we need
- *      to dispose of.
- * => caller must handle PG_WANTED case
- * => called with page's object locked, pageq's unlocked
- * => returns TRUE if page's object is still alive, FALSE if we
- *      killed the page's object.    if we return TRUE, then we
- *      return with the object locked.
- * => if (nextpgp != NULL) => we return the next page on the queue, and return
- *                              with the page queues locked [for pagedaemon]
- * => if (nextpgp == NULL) => we return with page queues unlocked [normal case]
- * => we kill the aobj if it is not referenced and we are suppose to
- *      kill it ("KILLME").
- */
-static boolean_t
-uao_releasepg(struct vm_page *pg, struct vm_page **nextpgp /* OUT */)
-{
-	struct uvm_aobj *aobj = (struct uvm_aobj *) pg->uobject;
-
-	KASSERT(pg->pg_flags & PG_RELEASED);
-
-	/*
- 	 * dispose of the page [caller handles PG_WANTED] and swap slot.
- 	 */
-	pmap_page_protect(pg, VM_PROT_NONE);
-	uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
-	uvm_lock_pageq();
-	if (nextpgp)
-		*nextpgp = TAILQ_NEXT(pg, pageq); /* next page for daemon */
-	uvm_pagefree(pg);
-	if (!nextpgp)
-		uvm_unlock_pageq();		/* keep locked for daemon */
-
-	/*
- 	 * if we're not killing the object, we're done.
- 	 */
-	if ((aobj->u_flags & UAO_FLAG_KILLME) == 0)
-		return TRUE;
-	KASSERT(aobj->u_obj.uo_refs == 0);
-
-	/*
- 	 * if there are still pages in the object, we're done for now.
- 	 */
-	if (aobj->u_obj.uo_npages != 0)
-		return TRUE;
-
-	KASSERT(TAILQ_EMPTY(&aobj->u_obj.memq));
-
-	/*
- 	 * finally, free the rest.
- 	 */
-	uao_free(aobj);
-
-	return FALSE;
-}
-
-
-/*
  * uao_dropswap:  release any swap resources from this aobj page.
  * 
  * => aobj must be locked or have a reference count of 0.
@@ -1476,7 +1340,6 @@ uao_pagein_page(struct uvm_aobj *aobj, int pageidx)
 		return FALSE;
 
 	}
-	KASSERT((pg->pg_flags & PG_RELEASED) == 0);
 
 	/*
 	 * ok, we've got the page now.