diff options
| author | Jeff Garzik <jeff@garzik.org> | 2010-11-16 02:10:29 -0500 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-16 13:33:23 -0800 |
| commit | f281233d3eba15fb225d21ae2e228fd4553d824a (patch) | |
| tree | 51134454ba8acb558735f90be5540f7d756483e3 /drivers/scsi/mpt2sas/mpt2sas_scsih.c | |
| parent | bdbd01ac444bffb3c9aefed3059d12554059b320 (diff) | |
SCSI host lock push-down
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.
The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.
Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)
Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.
Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/scsi/mpt2sas/mpt2sas_scsih.c')
| -rw-r--r-- | drivers/scsi/mpt2sas/mpt2sas_scsih.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c index 16e99b68635..1a96a00418a 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c +++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c @@ -3315,7 +3315,7 @@ _scsih_eedp_error_handling(struct scsi_cmnd *scmd, u16 ioc_status) * SCSI_MLQUEUE_HOST_BUSY if the entire host queue is full */ static int -_scsih_qcmd(struct scsi_cmnd *scmd, void (*done)(struct scsi_cmnd *)) +_scsih_qcmd_lck(struct scsi_cmnd *scmd, void (*done)(struct scsi_cmnd *)) { struct MPT2SAS_ADAPTER *ioc = shost_priv(scmd->device->host); struct MPT2SAS_DEVICE *sas_device_priv_data; @@ -3441,6 +3441,8 @@ _scsih_qcmd(struct scsi_cmnd *scmd, void (*done)(struct scsi_cmnd *)) return SCSI_MLQUEUE_HOST_BUSY; } +static DEF_SCSI_QCMD(_scsih_qcmd) + /** * _scsih_normalize_sense - normalize descriptor and fixed format sense data * @sense_buffer: sense data returned by target |