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path: root/drivers/xen/xen-balloon.c
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Diffstat (limited to 'drivers/xen/xen-balloon.c')
-rw-r--r--drivers/xen/xen-balloon.c22
1 files changed, 12 insertions, 10 deletions
diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index e7715cb62eef..e89136ab851e 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -59,6 +59,8 @@ static void watch_target(struct xenbus_watch *watch,
{
unsigned long long new_target;
int err;
+ static bool watch_fired;
+ static long target_diff;
err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
if (err != 1) {
@@ -69,7 +71,14 @@ static void watch_target(struct xenbus_watch *watch,
/* The given memory/target value is in KiB, so it needs converting to
* pages. PAGE_SHIFT converts bytes to pages, hence PAGE_SHIFT - 10.
*/
- balloon_set_new_target(new_target >> (PAGE_SHIFT - 10));
+ new_target >>= PAGE_SHIFT - 10;
+ if (watch_fired) {
+ balloon_set_new_target(new_target - target_diff);
+ return;
+ }
+
+ watch_fired = true;
+ target_diff = new_target - balloon_stats.target_pages;
}
static struct xenbus_watch target_watch = {
.node = "memory/target",
@@ -94,22 +103,15 @@ static struct notifier_block xenstore_notifier = {
.notifier_call = balloon_init_watcher,
};
-static int __init balloon_init(void)
+void xen_balloon_init(void)
{
- if (!xen_domain())
- return -ENODEV;
-
- pr_info("Initialising balloon driver\n");
-
register_balloon(&balloon_dev);
register_xen_selfballooning(&balloon_dev);
register_xenstore_notifier(&xenstore_notifier);
-
- return 0;
}
-subsys_initcall(balloon_init);
+EXPORT_SYMBOL_GPL(xen_balloon_init);
#define BALLOON_SHOW(name, format, args...) \
static ssize_t show_##name(struct device *dev, \