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Diffstat (limited to 'drivers/xen/balloon.c')
-rw-r--r--drivers/xen/balloon.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index fd933695f..bf4a23c7c 100644
--- 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. */