[PATCH] test9: another vm lockup bug - squashed

[PATCH] test9: another vm lockup bug - squashed

[Roger Larsson]

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Hi,

This is applicable on Riels latest addition.
(freepages v. zone->"limit")
That is probably not needed, and you should be able
to change your limits with this patch.

This patch adds equality check in several comparisons.

It is strictly only the one in __alloc_pages_limit
that is needed, it interacts with the test in
free_shortage. Without this patch you get stuck on
exactly zone->pages_min. Too few pages to alloc and
too many to free...


Ying Chen has reported that this patch cures his problem.

/RogerL

--
Home page:
  http://www.norran.net/nra02596/

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--- linux/mm/page_alloc.c.orig	Wed Oct  4 21:27:41 2000
+++ linux/mm/page_alloc.c	Wed Oct  4 21:32:17 2000
@@ -268,7 +268,7 @@ static struct page * __alloc_pages_limit
 				water_mark = z->pages_high;
 		}
 
-		if (z->free_pages + z->inactive_clean_pages > water_mark) {
+		if (z->free_pages + z->inactive_clean_pages >= water_mark) {
 			struct page *page = NULL;
 			/* If possible, reclaim a page directly. */
 			if (direct_reclaim && z->free_pages < z->pages_min + 8)
@@ -329,7 +329,7 @@ struct page * __alloc_pages(zonelist_t *
 	 * wake up bdflush.
 	 */
 	else if (free_shortage() && nr_inactive_dirty_pages > free_shortage()
-			&& nr_inactive_dirty_pages > freepages.high)
+			&& nr_inactive_dirty_pages >= freepages.high)
 		wakeup_bdflush(0);
 
 try_again:
@@ -347,7 +347,7 @@ try_again:
 		if (!z->size)
 			BUG();
 
-		if (z->free_pages > z->pages_low) {
+		if (z->free_pages >= z->pages_low) {
 			page = rmqueue(z, order);
 			if (page)
 				return page;