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Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a7785df2c944..1c4bedf500c5 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1206,6 +1206,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
bool no_tag = false;
int errors, queued;
blk_status_t ret = BLK_STS_OK;
+ bool no_budget_avail = false;
if (list_empty(list))
return false;
@@ -1224,6 +1225,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
hctx = rq->mq_hctx;
if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) {
blk_mq_put_driver_tag(rq);
+ no_budget_avail = true;
break;
}
@@ -1320,13 +1322,15 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
*
* If driver returns BLK_STS_RESOURCE and SCHED_RESTART
* bit is set, run queue after a delay to avoid IO stalls
- * that could otherwise occur if the queue is idle.
+ * that could otherwise occur if the queue is idle. We'll do
+ * similar if we couldn't get budget and SCHED_RESTART is set.
*/
needs_restart = blk_mq_sched_needs_restart(hctx);
if (!needs_restart ||
(no_tag && list_empty_careful(&hctx->dispatch_wait.entry)))
blk_mq_run_hw_queue(hctx, true);
- else if (needs_restart && (ret == BLK_STS_RESOURCE))
+ else if (needs_restart && (ret == BLK_STS_RESOURCE ||
+ no_budget_avail))
blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
blk_mq_update_dispatch_busy(hctx, true);