Hello, Recently I have been looking for opportunities to reduce command processing latency in the Linux SCSI initiator stack. I've noticed the following: - In drivers/scsi/scsi.c memory for the SCSI command and the SCSI sense data are allocated separately. Would it be a good idea to combine scsi_host_cmd_pool.cmd_slab and scsi_host_cmd_pool.sense_slab into a single kmem_cache or would this break something ? - While running an I/O workload that was using eight LUNs (two hosts with four LUNs each) I noticed huge lock contention on the spinlock in scsi_host_cmd_pool.cmd_slab. Has anyone already tried to modify the code in drivers/scsi/scsi.c such that there is one pool per LUN instead of one pool for all LUNs of all hosts ? Note: the scsi_sg_pools array in drivers/scsi/scsi_lib.c is also shared over all LUNs. Thanks, Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
