Change pgo_get() interface in preparation for running PGO_LOCKED in parallel.

- Do not allocate zero-fill'd pages in uao_get(), leave that for PGO_SYNCIO.
- Reduce cosmetic differences between uvn_get() and uao_get()

ok tb@

2 files changed, 15 insertions, 43 deletions

diff --git a/sys/uvm/uvm_aobj.c b/sys/uvm/uvm_aobj.c
index 33e2cb432ab..6ff2abee482 100644
--- a/sys/uvm/uvm_aobj.c
+++ b/sys/uvm/uvm_aobj.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_aobj.c,v 1.110 2024/04/13 23:44:11 jsg Exp $	*/
+/*	$OpenBSD: uvm_aobj.c,v 1.111 2024/11/27 10:41:38 mpi Exp $	*/
 /*	$NetBSD: uvm_aobj.c,v 1.39 2001/02/18 21:19:08 chs Exp $	*/
 
 /*
@@ -1012,7 +1012,6 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 		 * this if the data structures are locked (i.e. the first
 		 * time through).
  		 */
-
 		done = TRUE;	/* be optimistic */
 		gotpages = 0;	/* # of pages we got so far */
 
@@ -1022,35 +1021,17 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 			if (pps[lcv] == PGO_DONTCARE)
 				continue;
 
+			/* lookup page */
 			ptmp = uvm_pagelookup(uobj, current_offset);
 
 			/*
- 			 * if page is new, attempt to allocate the page,
-			 * zero-fill'd.
- 			 */
-			if (ptmp == NULL && uao_find_swslot(uobj,
-			    current_offset >> PAGE_SHIFT) == 0) {
-				ptmp = uvm_pagealloc(uobj, current_offset,
-				    NULL, UVM_PGA_ZERO);
-				if (ptmp) {
-					/* new page */
-					atomic_clearbits_int(&ptmp->pg_flags,
-					    PG_BUSY|PG_FAKE);
-					atomic_setbits_int(&ptmp->pg_flags,
-					    PQ_AOBJ);
-					UVM_PAGE_OWN(ptmp, NULL);
-				}
-			}
-
-			/*
 			 * to be useful must get a non-busy page
 			 */
-			if (ptmp == NULL ||
-			    (ptmp->pg_flags & PG_BUSY) != 0) {
+			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
 				if (lcv == centeridx ||
 				    (flags & PGO_ALLPAGES) != 0)
 					/* need to do a wait or I/O! */
-					done = FALSE;	
+					done = FALSE;
 				continue;
 			}
 
@@ -1061,7 +1042,6 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 			UVM_PAGE_OWN(ptmp, "uao_get1");
 			pps[lcv] = ptmp;
 			gotpages++;
-
 		}
 
 		/*
@@ -1069,12 +1049,7 @@ uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 		 * to unlock and do some waiting or I/O.
  		 */
 		*npagesp = gotpages;
-		if (done)
-			/* bingo! */
-			return VM_PAGER_OK;	
-		else
-			/* EEK!   Need to unlock and I/O */
-			return VM_PAGER_UNLOCK;
+		return done ? VM_PAGER_OK : VM_PAGER_UNLOCK;
 	}
 
 	/*
diff --git a/sys/uvm/uvm_vnode.c b/sys/uvm/uvm_vnode.c
index 8213f2699a4..a8aaa23cb45 100644
--- a/sys/uvm/uvm_vnode.c
+++ b/sys/uvm/uvm_vnode.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_vnode.c,v 1.134 2024/10/23 07:18:44 mpi Exp $	*/
+/*	$OpenBSD: uvm_vnode.c,v 1.135 2024/11/27 10:41:38 mpi Exp $	*/
 /*	$NetBSD: uvm_vnode.c,v 1.36 2000/11/24 20:34:01 chs Exp $	*/
 
 /*
@@ -970,7 +970,6 @@ uvn_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 
 		for (lcv = 0, current_offset = offset ; lcv < *npagesp ;
 		    lcv++, current_offset += PAGE_SIZE) {
-
 			/* do we care about this page?  if not, skip it */
 			if (pps[lcv] == PGO_DONTCARE)
 				continue;
@@ -978,12 +977,14 @@ uvn_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 			/* lookup page */
 			ptmp = uvm_pagelookup(uobj, current_offset);
 
-			/* to be useful must get a non-busy, non-released pg */
-			if (ptmp == NULL ||
-			    (ptmp->pg_flags & PG_BUSY) != 0) {
-				if (lcv == centeridx || (flags & PGO_ALLPAGES)
-				    != 0)
-					done = FALSE;	/* need to do a wait or I/O! */
+			/*
+			 * to be useful must get a non-busy page
+			 */
+			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
+				if (lcv == centeridx ||
+				    (flags & PGO_ALLPAGES) != 0)
+					/* need to do a wait or I/O! */
+					done = FALSE;
 				continue;
 			}
 
@@ -1014,12 +1015,8 @@ uvn_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
 		 * step 1c: now we've either done everything needed or we to
 		 * unlock and do some waiting or I/O.
 		 */
-
 		*npagesp = gotpages;		/* let caller know */
-		if (done)
-			return VM_PAGER_OK;		/* bingo! */
-		else
-			return VM_PAGER_UNLOCK;
+		return done ? VM_PAGER_OK : VM_PAGER_UNLOCK;
 	}
 
 	/*