From 2c3e50e5681bc6f76c68598a6a8771f4d3cd7edb Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@citrix.com>
Date: Fri, 5 Jun 2009 11:58:37 +0100
Subject: [PATCH] --- yaml --- r: 174433 b: refs/heads/master c:
 bc2c0303226ec716854d3c208c7f84fe7aa35cd7 h: refs/heads/master i:   174431:
 a30ade19c2a90be35cf00ea1cd1668f1f137887d v: v3

---
 [refs]                      |  2 +-
 trunk/drivers/xen/balloon.c | 31 +++++--------------------------
 2 files changed, 6 insertions(+), 27 deletions(-)

diff --git a/[refs] b/[refs]
index ddbe0632597f..c12ac1368e62 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3d65c9488cadd2f11bd4d60c7266e639ece5d0d6
+refs/heads/master: bc2c0303226ec716854d3c208c7f84fe7aa35cd7
diff --git a/trunk/drivers/xen/balloon.c b/trunk/drivers/xen/balloon.c
index 6eb62654410a..420433613584 100644
--- a/trunk/drivers/xen/balloon.c
+++ b/trunk/drivers/xen/balloon.c
@@ -66,8 +66,6 @@ struct balloon_stats {
 	/* We aim for 'current allocation' == 'target allocation'. */
 	unsigned long current_pages;
 	unsigned long target_pages;
-	/* We may hit the hard limit in Xen. If we do then we remember it. */
-	unsigned long hard_limit;
 	/*
 	 * Drivers may alter the memory reservation independently, but they
 	 * must inform the balloon driver so we avoid hitting the hard limit.
@@ -185,7 +183,7 @@ static void balloon_alarm(unsigned long unused)
 
 static unsigned long current_target(void)
 {
-	unsigned long target = min(balloon_stats.target_pages, balloon_stats.hard_limit);
+	unsigned long target = balloon_stats.target_pages;
 
 	target = min(target,
 		     balloon_stats.current_pages +
@@ -221,23 +219,10 @@ static int increase_reservation(unsigned long nr_pages)
 	set_xen_guest_handle(reservation.extent_start, frame_list);
 	reservation.nr_extents = nr_pages;
 	rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
-	if (rc < nr_pages) {
-		if (rc > 0) {
-			int ret;
-
-			/* We hit the Xen hard limit: reprobe. */
-			reservation.nr_extents = rc;
-			ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
-						   &reservation);
-			BUG_ON(ret != rc);
-		}
-		if (rc >= 0)
-			balloon_stats.hard_limit = (balloon_stats.current_pages + rc -
-						    balloon_stats.driver_pages);
+	if (rc < 0)
 		goto out;
-	}
 
-	for (i = 0; i < nr_pages; i++) {
+	for (i = 0; i < rc; i++) {
 		page = balloon_retrieve();
 		BUG_ON(page == NULL);
 
@@ -263,12 +248,12 @@ static int increase_reservation(unsigned long nr_pages)
 		__free_page(page);
 	}
 
-	balloon_stats.current_pages += nr_pages;
+	balloon_stats.current_pages += rc;
 
  out:
 	spin_unlock_irqrestore(&balloon_lock, flags);
 
-	return 0;
+	return rc < 0 ? rc : rc != nr_pages;
 }
 
 static int decrease_reservation(unsigned long nr_pages)
@@ -369,7 +354,6 @@ static void balloon_process(struct work_struct *work)
 static void balloon_set_new_target(unsigned long target)
 {
 	/* No need for lock. Not read-modify-write updates. */
-	balloon_stats.hard_limit   = ~0UL;
 	balloon_stats.target_pages = target;
 	schedule_work(&balloon_worker);
 }
@@ -428,7 +412,6 @@ static int __init balloon_init(void)
 	balloon_stats.balloon_low   = 0;
 	balloon_stats.balloon_high  = 0;
 	balloon_stats.driver_pages  = 0UL;
-	balloon_stats.hard_limit    = ~0UL;
 
 	init_timer(&balloon_timer);
 	balloon_timer.data = 0;
@@ -473,9 +456,6 @@ module_exit(balloon_exit);
 BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
 BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
 BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_high));
-BALLOON_SHOW(hard_limit_kb,
-	     (balloon_stats.hard_limit!=~0UL) ? "%lu\n" : "???\n",
-	     (balloon_stats.hard_limit!=~0UL) ? PAGES2KB(balloon_stats.hard_limit) : 0);
 BALLOON_SHOW(driver_kb, "%lu\n", PAGES2KB(balloon_stats.driver_pages));
 
 static ssize_t show_target_kb(struct sys_device *dev, struct sysdev_attribute *attr,
@@ -545,7 +525,6 @@ static struct attribute *balloon_info_attrs[] = {
 	&attr_current_kb.attr,
 	&attr_low_kb.attr,
 	&attr_high_kb.attr,
-	&attr_hard_limit_kb.attr,
 	&attr_driver_kb.attr,
 	NULL
 };