from netbsd: make anons dynamically allocated from pool.

this results in lesse kva waste due to static preallocation of those
for every phys page and also every swap page.
tested by beck krw miod

1 files changed, 25 insertions, 184 deletions

diff --git a/sys/uvm/uvm_anon.c b/sys/uvm/uvm_anon.c
index 0f6f7a0c1a6..b841a4f1e65 100644
--- a/sys/uvm/uvm_anon.c
+++ b/sys/uvm/uvm_anon.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_anon.c,v 1.21 2002/03/14 01:27:18 millert Exp $	*/
+/*	$OpenBSD: uvm_anon.c,v 1.22 2006/06/21 16:20:05 mickey Exp $	*/
 /*	$NetBSD: uvm_anon.c,v 1.10 2000/11/25 06:27:59 chs Exp $	*/
 
 /*
@@ -47,22 +47,7 @@
 #include <uvm/uvm.h>
 #include <uvm/uvm_swap.h>
 
-/*
- * anonblock_list: global list of anon blocks,
- * locked by swap_syscall_lock (since we never remove
- * anything from this list and we only add to it via swapctl(2)).
- */
-
-struct uvm_anonblock {
-	LIST_ENTRY(uvm_anonblock) list;
-	int count;
-	struct vm_anon *anons;
-};
-static LIST_HEAD(anonlist, uvm_anonblock) anonblock_list;
-
-
-static boolean_t anon_pagein(struct vm_anon *);
-
+struct pool uvm_anon_pool;
 
 /*
  * allocate anons
@@ -70,83 +55,9 @@ static boolean_t anon_pagein(struct vm_anon *);
 void
 uvm_anon_init()
 {
-	int nanon = uvmexp.free - (uvmexp.free / 16); /* XXXCDC ??? */
-
-	simple_lock_init(&uvm.afreelock);
-	LIST_INIT(&anonblock_list);
-
-	/*
-	 * Allocate the initial anons.
-	 */
-	uvm_anon_add(nanon);
-}
-
-/*
- * add some more anons to the free pool.  called when we add
- * more swap space.
- *
- * => swap_syscall_lock should be held (protects anonblock_list).
- */
-int
-uvm_anon_add(count)
-	int	count;
-{
-	struct uvm_anonblock *anonblock;
-	struct vm_anon *anon;
-	int lcv, needed;
-
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanonneeded += count;
-	needed = uvmexp.nanonneeded - uvmexp.nanon;
-	simple_unlock(&uvm.afreelock);
-
-	if (needed <= 0) {
-		return 0;
-	}
- 
-	anon = (void *)uvm_km_alloc(kernel_map, sizeof(*anon) * needed);
-
-	/* XXX Should wait for VM to free up. */
-	if (anon == NULL) {
-		printf("uvm_anon_add: can not allocate %d anons\n", needed);
-		panic("uvm_anon_add");
-	}
-
-	MALLOC(anonblock, void *, sizeof(*anonblock), M_UVMAMAP, M_WAITOK);
-
-	anonblock->count = needed;
-	anonblock->anons = anon;
-	LIST_INSERT_HEAD(&anonblock_list, anonblock, list);
-	memset(anon, 0, sizeof(*anon) * needed);
- 
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanon += needed;
-	uvmexp.nfreeanon += needed;
-	for (lcv = 0; lcv < needed; lcv++) {
-		simple_lock_init(&anon->an_lock);
-		anon[lcv].u.an_nxt = uvm.afree;
-		uvm.afree = &anon[lcv];
-		simple_lock_init(&uvm.afree->an_lock);
-	}
-	simple_unlock(&uvm.afreelock);
-	return 0;
-}
-
-/*
- * remove anons from the free pool.
- */
-void
-uvm_anon_remove(count)
-	int count;
-{
-	/*
-	 * we never actually free any anons, to avoid allocation overhead.
-	 * XXX someday we might want to try to free anons.
-	 */
-
-	simple_lock(&uvm.afreelock);
-	uvmexp.nanonneeded -= count;
-	simple_unlock(&uvm.afreelock);
+	pool_init(&uvm_anon_pool, sizeof(struct vm_anon), 0, 0, 0, "anonpl",
+	    &pool_allocator_nointr);
+	pool_sethiwat(&uvm_anon_pool, uvmexp.free / 16);
 }
 
 /*
@@ -155,19 +66,17 @@ uvm_anon_remove(count)
 struct vm_anon *
 uvm_analloc()
 {
-	struct vm_anon *a;
-
-	simple_lock(&uvm.afreelock);
-	a = uvm.afree;
-	if (a) {
-		uvm.afree = a->u.an_nxt;
-		uvmexp.nfreeanon--;
-		a->an_ref = 1;
-		a->an_swslot = 0;
-		a->u.an_page = NULL;		/* so we can free quickly */
+	struct vm_anon *anon;
+
+	anon = pool_get(&uvm_anon_pool, PR_NOWAIT);
+	if (anon) {
+		simple_lock_init(&anon->an_lock);
+		anon->an_ref = 1;
+		anon->an_page = NULL;
+		anon->an_swslot = 0;
+		simple_lock(&anon->an_lock);
 	}
-	simple_unlock(&uvm.afreelock);
-	return(a);
+	return(anon);
 }
 
 /*
@@ -190,7 +99,7 @@ uvm_anfree(anon)
 	 * get page
 	 */
 
-	pg = anon->u.an_page;
+	pg = anon->an_page;
 
 	/*
 	 * if there is a resident page and it is loaned, then anon may not
@@ -257,11 +166,10 @@ uvm_anfree(anon)
 	 * now that we've stripped the data areas from the anon, free the anon
 	 * itself!
 	 */
-	simple_lock(&uvm.afreelock);
-	anon->u.an_nxt = uvm.afree;
-	uvm.afree = anon;
-	uvmexp.nfreeanon++;
-	simple_unlock(&uvm.afreelock);
+	KASSERT(anon->an_page == NULL);
+	KASSERT(anon->an_swslot == 0);
+
+	pool_put(&uvm_anon_pool, anon);
 	UVMHIST_LOG(maphist,"<- done!",0,0,0,0);
 }
 
@@ -284,7 +192,7 @@ uvm_anon_dropswap(anon)
 	uvm_swap_free(anon->an_swslot, 1);
 	anon->an_swslot = 0;
 
-	if (anon->u.an_page == NULL) {
+	if (anon->an_page == NULL) {
 		/* this page is no longer only in swap. */
 		simple_lock(&uvm.swap_data_lock);
 		uvmexp.swpgonly--;
@@ -325,7 +233,7 @@ uvm_anon_lockloanpg(anon)
 	 * not produce an incorrect result.
 	 */
 
-	while (((pg = anon->u.an_page) != NULL) && pg->loan_count != 0) {
+	while (((pg = anon->an_page) != NULL) && pg->loan_count != 0) {
 
 		/*
 		 * quickly check to see if the page has an object before
@@ -387,73 +295,6 @@ uvm_anon_lockloanpg(anon)
 	return(pg);
 }
 
-
-
-/*
- * page in every anon that is paged out to a range of swslots.
- * 
- * swap_syscall_lock should be held (protects anonblock_list).
- */
-
-boolean_t
-anon_swap_off(startslot, endslot)
-	int startslot, endslot;
-{
-	struct uvm_anonblock *anonblock;
-
-	for (anonblock = LIST_FIRST(&anonblock_list);
-	     anonblock != NULL;
-	     anonblock = LIST_NEXT(anonblock, list)) {
-		int i;
-
-		/*
-		 * loop thru all the anons in the anonblock,
-		 * paging in where needed.
-		 */
-
-		for (i = 0; i < anonblock->count; i++) {
-			struct vm_anon *anon = &anonblock->anons[i];
-			int slot;
-
-			/*
-			 * lock anon to work on it.
-			 */
-
-			simple_lock(&anon->an_lock);
-
-			/*
-			 * is this anon's swap slot in range?
-			 */
-
-			slot = anon->an_swslot;
-			if (slot >= startslot && slot < endslot) {
-				boolean_t rv;
-
-				/*
-				 * yup, page it in.
-				 */
-
-				/* locked: anon */
-				rv = anon_pagein(anon);
-				/* unlocked: anon */
-
-				if (rv) {
-					return rv;
-				}
-			} else {
-
-				/*
-				 * nope, unlock and proceed.
-				 */
-
-				simple_unlock(&anon->an_lock);
-			}
-		}
-	}
-	return FALSE;
-}
-
-
 /*
  * fetch an anon's page.
  *
@@ -461,8 +302,8 @@ anon_swap_off(startslot, endslot)
  * => returns TRUE if pagein was aborted due to lack of memory.
  */
 
-static boolean_t
-anon_pagein(anon)
+boolean_t
+uvm_anon_pagein(anon)
 	struct vm_anon *anon;
 {
 	struct vm_page *pg;
@@ -504,7 +345,7 @@ anon_pagein(anon)
 	 * mark it as dirty, clear its swslot and un-busy it.
 	 */
 
-	pg = anon->u.an_page;
+	pg = anon->an_page;
 	uobj = pg->uobject;
 	uvm_swap_free(anon->an_swslot, 1);
 	anon->an_swslot = 0;