block: avoid building too big plug list
[pandora-kernel.git] / block / blk-core.c
index d2f8f40..a564852 100644 (file)
@@ -1302,7 +1302,10 @@ get_rq:
                                plug->should_sort = 1;
                }
                list_add_tail(&req->queuelist, &plug->list);
+               plug->count++;
                drive_stat_acct(req, 1);
+               if (plug->count >= BLK_MAX_REQUEST_COUNT)
+                       blk_flush_plug_list(plug, false);
        } else {
                spin_lock_irq(q->queue_lock);
                add_acct_request(q, req, where);
@@ -2626,6 +2629,7 @@ void blk_start_plug(struct blk_plug *plug)
        INIT_LIST_HEAD(&plug->list);
        INIT_LIST_HEAD(&plug->cb_list);
        plug->should_sort = 0;
+       plug->count = 0;
 
        /*
         * If this is a nested plug, don't actually assign it. It will be
@@ -2709,6 +2713,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                return;
 
        list_splice_init(&plug->list, &list);
+       plug->count = 0;
 
        if (plug->should_sort) {
                list_sort(NULL, &list, plug_rq_cmp);