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Date:      Sat, 12 May 2012 19:22:58 +0000 (UTC)
From:      Attilio Rao <attilio@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-user@freebsd.org
Subject:   svn commit: r235349 - user/attilio/vmcontention/sys/vm
Message-ID:  <201205121922.q4CJMwBs047730@svn.freebsd.org>
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Author: attilio
Date: Sat May 12 19:22:57 2012
New Revision: 235349
URL: http://svn.freebsd.org/changeset/base/235349

Log:
  - Fix a bug where lookupn can wrap up looking for the pages to scan,
    returning a non correct very low address again.
  - Stub out vm_lookup_foreach as it is not used

Modified:
  user/attilio/vmcontention/sys/vm/vm_radix.c
  user/attilio/vmcontention/sys/vm/vm_radix.h

Modified: user/attilio/vmcontention/sys/vm/vm_radix.c
==============================================================================
--- user/attilio/vmcontention/sys/vm/vm_radix.c	Sat May 12 18:11:26 2012	(r235348)
+++ user/attilio/vmcontention/sys/vm/vm_radix.c	Sat May 12 19:22:57 2012	(r235349)
@@ -638,15 +638,37 @@ vm_radix_lookupn(struct vm_radix *rtree,
 			if (end != 0 && start >= end)
 				goto out;
 			val = vm_radix_match(rnode->rn_child[slot], color);
-			if (val == NULL)
+			if (val == NULL) {
+
+				/*
+				 * The start address can wrap at the
+				 * VM_RADIX_MAXVAL value.
+				 * We need to make sure that start address
+				 * point to the next chunk (even if wrapping)
+				 * to stay consistent with default scanning
+				 * behaviour. Also, because of the nature
+				 * of the wrapping, the wrap up checks must
+				 * be done after all the necessary controls
+				 * on start are completed.
+				 */
+				if ((VM_RADIX_MAXVAL - start) == 0) {
+					start++;
+					goto out;
+				}
 				continue;
+			}
 			CTR4(KTR_VM,
 			    "lookupn: tree %p index %ju slot %d found child %p",
 			    rtree, (uintmax_t)start, slot, val);
 			out[outidx] = val;
 			if (++outidx == cnt)
 				goto out;
-		}
+			if ((VM_RADIX_MAXVAL - start) == 0) {
+				start++;
+				goto out;
+			}
+		} 
+		MPASS((VM_RADIX_MAXVAL - start) != 0);
 		if (end != 0 && start >= end)
 			break;
 	}
@@ -655,6 +677,7 @@ out:
 	return (outidx);
 }
 
+#if 0
 void
 vm_radix_foreach(struct vm_radix *rtree, vm_pindex_t start, vm_pindex_t end,
     int color, void (*iter)(void *))
@@ -678,6 +701,7 @@ vm_radix_foreach(struct vm_radix *rtree,
 			return;
 	}
 }
+#endif
 
 
 /*

Modified: user/attilio/vmcontention/sys/vm/vm_radix.h
==============================================================================
--- user/attilio/vmcontention/sys/vm/vm_radix.h	Sat May 12 18:11:26 2012	(r235348)
+++ user/attilio/vmcontention/sys/vm/vm_radix.h	Sat May 12 19:22:57 2012	(r235349)
@@ -64,8 +64,6 @@ int	vm_radix_lookupn(struct vm_radix *, 
 void	*vm_radix_lookup_le(struct vm_radix *, vm_pindex_t, int);
 void	vm_radix_reclaim_allnodes(struct vm_radix *);
 void	*vm_radix_remove(struct vm_radix *, vm_pindex_t, int);
-void	vm_radix_foreach(struct vm_radix *, vm_pindex_t, vm_pindex_t, int,
-	    void (*)(void *));
 
 /*
  * Look up any entry at a position greater or equal to index.

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