This patchset introduces some patches to much improve DQ lockout for sending commands to the HW. Currently we lockout the complete DQ when building and sending a task to the HW. The reason we did this was because once we allocate a slot in the DQ to use, if we fail the send the slot then the slot must be reused. We cannot simply forget about the slot and allow subsequent slots in the DQ to be used. To improve this and reduce this DQ lockout, we change the order in which we allocate and build a slot. We must now do any steps *which may fail* before allocating the slot. So this means that once we allocate the slot we cannot fail to send it. By doing this we can greatly reduce the periods in which we lock the DQ for building and sending a slot, allowing more parallelism in sending commands to HW. Overall this DQ locking improvement has shown to improve performance, and also will make MQ perform better if ever turned on. Xiang Chen (5): scsi: hisi_sas: relocate smp sg map scsi: hisi_sas: make return type of prep functions void scsi: hisi_sas: allocate slot buffer earlier scsi: hisi_sas: Don't lock DQ for complete task sending scsi: hisi_sas: Use device lock to protect slot alloc/free Xiaofei Tan (1): scsi: hisi_sas: add check of device in hisi_sas_task_exec() drivers/scsi/hisi_sas/hisi_sas.h | 12 +- drivers/scsi/hisi_sas/hisi_sas_main.c | 264 ++++++++++++++++++--------------- drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 88 ++++------- drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 109 +++++--------- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 107 +++++-------- 5 files changed, 248 insertions(+), 332 deletions(-) -- 1.9.1
