On Thu, Dec 03, 2020 at 09:26:35AM +0800, 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. > > V2: > - add reviewed-by > - adjust commit log of patch 3 > > Ming Lei (3): > blk-mq: add new API of blk_mq_hctx_set_fq_lock_class > nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class > Revert "block: Fix a lockdep complaint triggered by request queue > flushing" > > block/blk-flush.c | 30 +++++++++++++++++++++++++----- > block/blk.h | 1 - > drivers/nvme/target/loop.c | 10 ++++++++++ > include/linux/blk-mq.h | 3 +++ > 4 files changed, 38 insertions(+), 6 deletions(-) > > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Qian Cai <cai@xxxxxxxxxx> > Cc: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx> > Cc: John Garry <john.garry@xxxxxxxxxx> > Cc: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx> > Cc: Bart Van Assche <bvanassche@xxxxxxx> > Cc: Hannes Reinecke <hare@xxxxxxx> > -- > 2.28.0 > Hello Jens, Ping... -- Ming