From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Greetings all,
This series contains the second round of a whole-sale conversion for completely
dropping struct Scsi_Host->host_lock usage within scsi_dispatch_cmd() for
the ML internal scsi_cmd_get_serial() and external SHT->queuecommand() LLD callers.
The main changes from comments from v1 -> v2 are:
*) Make scsi_cmd_get_serial() use atomic_t and disable it's usage by default.
*) Drop struct Scsi_Host->host_lock usage in scsi_dispatch_cmd()
For the v2 series, patch #1 converts struct Scsi_Host->cmd_serial_number to
atomic_t and adds struct Scsi_Host->use_serial_number to enabled usage. This
patch also follows Joe Eykholt suggestion of using a +2 for each scsi_cmd_get_serial()
to ensure that the counter always wraps to a non-zero value.
Patch #2 completely removes host_lock usage from scsi_dispatch_cmd().
Patch #3 -> #6 remove the legacy host_lock lock() -> do_work() -> unlock()
optimization from generic libiscsi, libsas, libfc and libata ->queuecommand()
callers respectively.
And patches #7 -> #11 do the same conversion legacy host_lock lock() -> do_work() ->
unlock() for lpfc, qla4xxx, qla2xxx, fnic, and buslogic LLDs specific ->queuecommand()
callers.
There may still be more LLDs which use this optimization, so please let me know if
there is another piece of SHT->queuecommand() caller code that does this legacy
optimization not in this list that need to be updated. I will be sure to CC
the right driver maintainers and CC linux-scsi as I come across any more
conversions.
Many thanks to James Bottomley, Andi Keen, Joe Eykholt, Vasu Dev and
Tim Chen for their code and comments!
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
Nicholas Bellinger (11):
scsi: Convert struct Scsi_Host->cmd_serial_number to atomic_t
scsi: Drop struct Scsi_Host->host_lock usage in scsi_dispatch_cmd()
libiscsi: Remove host_lock unlock() + lock() from
iscsi_queuecommand()
libsas: Remove host_lock unlock() + lock() from sas_queuecommand()
libfc: Remove host_lock unlock() + lock() from fc_queuecommand()
libata: Remove host_lock unlock() + lock() from ata_scsi_queuecmd()
lpfc: Remove host_lock unlock() + lock() from lpfc_queuecommand()
qla4xxx: Remove host_lock unlock() + lock() from
qla4xxx_queuecommand()
qla2xxx: Remove host_lock unlock() + lock() from
qla2xxx_queuecommand()
fnic: Remove host_lock unlock() + lock() from fnic_queuecommand()
buslogic: Remove host_lock unlock() + lock() from
BusLogic_QueueCommand()
drivers/ata/libata-scsi.c | 2 --
drivers/scsi/BusLogic.c | 4 ----
drivers/scsi/fnic/fnic_scsi.c | 9 ---------
drivers/scsi/hosts.c | 4 ++++
drivers/scsi/libfc/fc_fcp.c | 5 +----
drivers/scsi/libiscsi.c | 4 ----
drivers/scsi/libsas/sas_scsi_host.c | 5 -----
drivers/scsi/lpfc/lpfc_scsi.c | 2 --
drivers/scsi/qla2xxx/qla_os.c | 7 ++-----
drivers/scsi/qla4xxx/ql4_os.c | 8 +-------
drivers/scsi/scsi.c | 17 +++++++++++------
include/scsi/scsi_host.h | 8 +++++---
12 files changed, 24 insertions(+), 51 deletions(-)
--
1.7.2.3
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