Linux 3.14

[~andy/linux] / lib / dynamic_queue_limits.c

diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
index c87eb76f2fd4f0e778ea74a915a0108e5202f8ce..0777c5a45fa04f3464100dfdf24dbee15aecfd98 100644 (file)
--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -11,22 +11,26 @@
 #include <linux/dynamic_queue_limits.h>
 
 #define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0)
+#define AFTER_EQ(A, B) ((int)((A) - (B)) >= 0)
 
 /* Records completed count and recalculates the queue limit */
 void dql_completed(struct dql *dql, unsigned int count)
 {
        unsigned int inprogress, prev_inprogress, limit;
-       unsigned int ovlimit, all_prev_completed, completed;
+       unsigned int ovlimit, completed, num_queued;
+       bool all_prev_completed;
+
+       num_queued = ACCESS_ONCE(dql->num_queued);
 
        /* Can't complete more than what's in queue */
-       BUG_ON(count > dql->num_queued - dql->num_completed);
+       BUG_ON(count > num_queued - dql->num_completed);
 
        completed = dql->num_completed + count;
        limit = dql->limit;
-       ovlimit = POSDIFF(dql->num_queued - dql->num_completed, limit);
-       inprogress = dql->num_queued - completed;
+       ovlimit = POSDIFF(num_queued - dql->num_completed, limit);
+       inprogress = num_queued - completed;
        prev_inprogress = dql->prev_num_queued - dql->num_completed;
-       all_prev_completed = POSDIFF(completed, dql->prev_num_queued);
+       all_prev_completed = AFTER_EQ(completed, dql->prev_num_queued);
 
        if ((ovlimit && !inprogress) ||
            (dql->prev_ovlimit && all_prev_completed)) {
@@ -104,7 +108,7 @@ void dql_completed(struct dql *dql, unsigned int count)
        dql->prev_ovlimit = ovlimit;
        dql->prev_last_obj_cnt = dql->last_obj_cnt;
        dql->num_completed = completed;
-       dql->prev_num_queued = dql->num_queued;
+       dql->prev_num_queued = num_queued;
 }
 EXPORT_SYMBOL(dql_completed);