Index: head/sys/vm/vm_page.c
===================================================================
--- head/sys/vm/vm_page.c
+++ head/sys/vm/vm_page.c
@@ -222,10 +222,12 @@
 		vmd = VM_DOMAIN(domain);
 
 		/*
-		 * Don't allow the page caches to take up more than .25% of
-		 * memory.
+		 * Don't allow the page caches to take up more than .1875% of
+		 * memory.  A UMA bucket contains at most 256 free pages, and we
+		 * have two buckets per CPU per free pool.
 		 */
-		if (vmd->vmd_page_count / 400 < 256 * mp_ncpus * VM_NFREEPOOL)
+		if (vmd->vmd_page_count / 600 < 2 * 256 * mp_ncpus *
+		    VM_NFREEPOOL)
 			continue;
 		for (pool = 0; pool < VM_NFREEPOOL; pool++) {
 			pgcache = &vmd->vmd_pgcache[pool];