Merge branches 'for-4.3/chicony', 'for-4.3/cp2112', 'for-4.3/i2c-hid', 'for-4.3/lenov...

[karo-tx-linux.git] / drivers / xen / balloon.c

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index fd933695f2328f29c2493ee751f22230ec68cbb1..bf4a23c7c5918f6849e764a8376c3608cc591933 100644 (file)
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -472,7 +472,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
 }
 
 /*
- * We avoid multiple worker processes conflicting via the balloon mutex.
+ * As this is a work item it is guaranteed to run as a single instance only.
  * We may of course race updates of the target counts (which are protected
  * by the balloon lock), or with changes to the Xen hard limit, but we will
  * recover from these in time.
@@ -482,9 +482,10 @@ static void balloon_process(struct work_struct *work)
        enum bp_state state = BP_DONE;
        long credit;
 
-       mutex_lock(&balloon_mutex);
 
        do {
+               mutex_lock(&balloon_mutex);
+
                credit = current_credit();
 
                if (credit > 0) {
@@ -499,17 +500,15 @@ static void balloon_process(struct work_struct *work)
 
                state = update_schedule(state);
 
-#ifndef CONFIG_PREEMPT
-               if (need_resched())
-                       schedule();
-#endif
+               mutex_unlock(&balloon_mutex);
+
+               cond_resched();
+
        } while (credit && state == BP_DONE);
 
        /* Schedule more work if there is some still to be done. */
        if (state == BP_EAGAIN)
                schedule_delayed_work(&balloon_worker, balloon_stats.schedule_delay * HZ);
-
-       mutex_unlock(&balloon_mutex);
 }
 
 /* Resets the Xen limit, sets new target, and kicks off processing. */