xen/balloon: the balloon_lock is useless
The balloon_lock is useless, since it protects nothing against nothing.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index df26ee9..77b5dc3 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -195,7 +195,7 @@
static int increase_reservation(unsigned long nr_pages)
{
- unsigned long pfn, i, flags;
+ unsigned long pfn, i;
struct page *page;
long rc;
struct xen_memory_reservation reservation = {
@@ -207,8 +207,6 @@
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
- spin_lock_irqsave(&xen_reservation_lock, flags);
-
page = balloon_first_page();
for (i = 0; i < nr_pages; i++) {
BUG_ON(page == NULL);
@@ -251,14 +249,12 @@
balloon_stats.current_pages += rc;
out:
- spin_unlock_irqrestore(&xen_reservation_lock, flags);
-
return rc < 0 ? rc : rc != nr_pages;
}
static int decrease_reservation(unsigned long nr_pages)
{
- unsigned long pfn, i, flags;
+ unsigned long pfn, i;
struct page *page;
int need_sleep = 0;
int ret;
@@ -296,8 +292,6 @@
kmap_flush_unused();
flush_tlb_all();
- spin_lock_irqsave(&xen_reservation_lock, flags);
-
/* No more mappings: invalidate P2M and add to balloon. */
for (i = 0; i < nr_pages; i++) {
pfn = mfn_to_pfn(frame_list[i]);
@@ -312,8 +306,6 @@
balloon_stats.current_pages -= nr_pages;
- spin_unlock_irqrestore(&xen_reservation_lock, flags);
-
return need_sleep;
}