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.
Ming Lei (3): scsi: introduce scsi_host_busy() 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 <osan...@fb.com>, Cc: "Martin K. Petersen" <martin.peter...@oracle.com>, Cc: James Bottomley <james.bottom...@hansenpartnership.com>, Cc: Christoph Hellwig <h...@lst.de>, Cc: Don Brace <don.br...@microsemi.com> Cc: Kashyap Desai <kashyap.de...@broadcom.com> Cc: Mike Snitzer <snit...@redhat.com> Cc: Hannes Reinecke <h...@suse.de> Cc: Laurence Oberman <lober...@redhat.com> -- 2.9.5