When there is a scsi command timed-out or failed, the scsi eh tries a thorugh recovery, which is necessary for non-redundant systems. However, the thorugh recovery usually takes much time, which is not acceptable for misson critical systems. To improve this latency, if we are working on a redundant system, we should avoid the scsi eh for its long time failing recovery, and quick failover to another path. This set of patches is trying to implement above. NOTE: the userland tools need to eusure the environment restriction, which will be implemented later. Thanks, Ren Ren Mingxin (5): scsi: rename return code FAST_IO_FAIL to FAST_IO FC transport: Add interface to specify fast io level for timed-out cmds SAS transport: Add interface to specify fast io level for timed-out cmds lpfc: Allow fast timed-out io recovery mptfusion: Allow fast timed-out io recovery drivers/message/fusion/mptscsih.c | 29 ++++++++- drivers/scsi/lpfc/lpfc_scsi.c | 34 ++++++++++ drivers/scsi/scsi_error.c | 18 ++--- drivers/scsi/scsi_sas_internal.h | 4 - drivers/scsi/scsi_transport_fc.c | 112 ++++++++++++++++++++++++++++++++++-- drivers/scsi/scsi_transport_iscsi.c | 6 - drivers/scsi/scsi_transport_sas.c | 103 ++++++++++++++++++++++++++++++++- include/scsi/scsi.h | 2 include/scsi/scsi_transport_fc.h | 11 +++ include/scsi/scsi_transport_sas.h | 8 ++ 10 files changed, 303 insertions(+), 24 deletions(-) -- 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