xen: Add support for preemption
Add Xen support for preemption. This is mostly a cleanup of existing
preempt_enable/disable calls, or just comments to explain the current
usage.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
diff --git a/arch/i386/xen/mmu.c b/arch/i386/xen/mmu.c
index bc49ef8..f431cf1 100644
--- a/arch/i386/xen/mmu.c
+++ b/arch/i386/xen/mmu.c
@@ -38,6 +38,7 @@
*
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
*/
+#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/bug.h>
#include <linux/sched.h>
@@ -531,5 +532,7 @@
drop_mm_ref(mm);
put_cpu();
+ spin_lock(&mm->page_table_lock);
xen_pgd_unpin(mm->pgd);
+ spin_unlock(&mm->page_table_lock);
}