Hi, This patches removes the expensive atomic opeation on host-wide counter of .host_busy for scsi-mq, and it is observed that IOPS can be increased by 15% with this change in IO test over scsi_debug. V2: - merge patch 1&2 into one patch - run more tests(blktests, xfstests, ...), and not see regression Ming Lei (2): scsi: read host_busy via scsi_host_busy() scsi: avoid to hold host-wide counter of host_busy for scsi_mq drivers/scsi/advansys.c | 8 ++++---- drivers/scsi/hosts.c | 32 +++++++++++++++++++++++++++++++ drivers/scsi/libsas/sas_scsi_host.c | 4 ++-- drivers/scsi/megaraid/megaraid_sas_base.c | 2 +- drivers/scsi/mpt3sas/mpt3sas_base.c | 4 ++-- drivers/scsi/qlogicpti.c | 2 +- drivers/scsi/scsi.c | 2 +- drivers/scsi/scsi_error.c | 6 +++--- drivers/scsi/scsi_lib.c | 23 ++++++++++++++++------ drivers/scsi/scsi_sysfs.c | 2 +- include/scsi/scsi_host.h | 1 + 11 files changed, 65 insertions(+), 21 deletions(-) Cc: Omar Sandoval <osandov@xxxxxx>, Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>, Cc: James Bottomley <james.bottomley@xxxxxxxxxxxxxxxxxxxxx>, Cc: Christoph Hellwig <hch@xxxxxx>, Cc: Don Brace <don.brace@xxxxxxxxxxxxx> Cc: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx> Cc: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: Hannes Reinecke <hare@xxxxxxx> Cc: Laurence Oberman <loberman@xxxxxxxxxx> Cc: Bart Van Assche <bart.vanassche@xxxxxxx> -- 2.9.5
