This warning is harmless, please try the following patch:
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From 7b2b5139bfef80f44d1b1424e09ab35b715fbfdb Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Tue, 27 Mar 2018 19:54:23 +0800
Subject: [PATCH] blk-mq: only run mapped hw queues in blk_mq_run_hw_queues()
From commit 20e4d813931961fe ("blk-mq: simplify queue mapping & schedule
with each possisble CPU") on, it should be easier to see unmapped hctx
in some CPU topo, such as, hctx may not be mapped to any CPU.
This patch avoids the warning in __blk_mq_delay_run_hw_queue() by
checking if the hctx is mapped in blk_mq_run_hw_queues().
Reported-by: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Fixes: 20e4d813931961fe ("blk-mq: simplify queue mapping & schedule with each possisble CPU")
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
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Hi Ming,
thanks a lot for the patch. I tried it on top of our 4.16-rc7 branch and
it works well.
I ran a small regression test set against it and I did not notice any
warnings or other obvious impacts.
Regards,
Stefan
