From: Jens Axboe <axboe@fb.com>
Date: Wed, 25 Jun 2014 14:22:34 +0000 (-0600)
Subject: blk-mq: blk_mq_start_hw_queue() should use blk_mq_run_hw_queue()
X-Git-Tag: firefly_0821_release~176^2~3694^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0ffbce80c263821161190f20e74a12f7aa8eab7b;p=firefly-linux-kernel-4.4.55.git

blk-mq: blk_mq_start_hw_queue() should use blk_mq_run_hw_queue()

Currently it calls __blk_mq_run_hw_queue(), which depends on the
CPU placement being correct. This means it's not possible to call
blk_mq_start_hw_queues(q) from a context that is correct for all
queues, leading to triggering the

WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));

in __blk_mq_run_hw_queue().

Reported-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0ef2dc7f01bf..ad69ef657e85 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -878,7 +878,7 @@ void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
 	clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
 
 	preempt_disable();
-	__blk_mq_run_hw_queue(hctx);
+	blk_mq_run_hw_queue(hctx, false);
 	preempt_enable();
 }
 EXPORT_SYMBOL(blk_mq_start_hw_queue);