PrioritizedQueue: cap costs at max_tokens_per_subqueue

Otherwise, you can get a recovery op in the queue which has a cost
higher than the max token value.  It won't get serviced until all other
queues also do not have enough tokens and higher priority queues are
empty.

Fixes: #7706
Signed-off-by: Samuel Just <sam.just@inktank.com>
(cherry picked from commit 2722a0a487e77ea2aa0d18caec0bdac50cb6a264)

diff --git a/src/common/PrioritizedQueue.h b/src/common/PrioritizedQueue.h
index 6dcb519da400e4d81f59fceb93098f68d908dda5..d3b46b3636cbf3e1c67910341fc0579b4d57b1ed 100644 (file)
--- a/src/common/PrioritizedQueue.h
+++ b/src/common/PrioritizedQueue.h
@@ -311,12 +311,16 @@ public:
   void enqueue(K cl, unsigned priority, unsigned cost, T item) {
     if (cost < min_cost)
       cost = min_cost;
+    if (cost > max_tokens_per_subqueue)
+      cost = max_tokens_per_subqueue;
     create_queue(priority)->enqueue(cl, cost, item);
   }
 
   void enqueue_front(K cl, unsigned priority, unsigned cost, T item) {
     if (cost < min_cost)
       cost = min_cost;
+    if (cost > max_tokens_per_subqueue)
+      cost = max_tokens_per_subqueue;
     create_queue(priority)->enqueue_front(cl, cost, item);
   }