Re: [PATCH V2 0/3] blk-mq/nvme-loop: use nvme-loop's lock class for addressing lockdep false positive warning
From: Jens Axboe <axboe@kernel.dk>
Date: 2020-12-08 03:31:29
On 12/2/20 6:26 PM, Ming Lei wrote:
Hi,
Qian reported there is hang during booting when shared host tagset is
introduced on megaraid sas. Sumit reported the whole SCSI probe takes
about ~45min in his test.
Turns out it is caused by nr_hw_queues increased, especially commit
b3c6a5997541("block: Fix a lockdep complaint triggered by request queue flushing")
adds synchronize_rcu() for each hctx's release handler.
Address the original lockdep false positive warning by simpler way, then
long scsi probe can be avoided with lockdep enabled.Applied, thanks. -- Jens Axboe