diff options
| author | Darrick J. Wong <djwong@us.ibm.com> | 2006-08-30 23:18:33 +0200 |
|---|---|---|
| committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2006-08-30 23:30:06 +0200 |
| commit | f19eaa7f53736449a6eac89c3863eca2c64d5913 (patch) | |
| tree | dd60f697af06bf3b6b1ece3fa7a29485ff2b4e92 /drivers/scsi/aic94xx/aic94xx_init.c | |
| parent | [SCSI] aic94xx: add MODULE_FIRMWARE tag (diff) | |
| download | linux-f19eaa7f53736449a6eac89c3863eca2c64d5913.tar.xz linux-f19eaa7f53736449a6eac89c3863eca2c64d5913.zip | |
[SCSI] aic94xx: Increase can_queue for better performance
This patch sets can_queue in the aic94xx driver's scsi_host to better
performing values than what's there currently. It seems that
asd_ha->seq.can_queue reflects the number of requests that can be
queued per controller; so long as there's one scsi_host per
controller, it seems logical that the scsi_host ought to have the same
can_queue value. To the best of my (still limited) knowledge, this
method provides the correct value.
The effect of leaving this value set to 1 is terrible performance in
the case of either (a) certain Maxtor SAS drives flying solo or (b)
flooding several disks with I/O simultaneously (md-raid). There may be
more scenarios where we see similar problems that I haven't uncovered.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/aic94xx/aic94xx_init.c')
| -rw-r--r-- | drivers/scsi/aic94xx/aic94xx_init.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c index 3ec2e46f80c6..69aa70887530 100644 --- a/drivers/scsi/aic94xx/aic94xx_init.c +++ b/drivers/scsi/aic94xx/aic94xx_init.c @@ -620,6 +620,8 @@ static int __devinit asd_pci_probe(struct pci_dev *dev, asd_ha->hw_prof.bios.present ? "build " : "not present", asd_ha->hw_prof.bios.bld); + shost->can_queue = asd_ha->seq.can_queue; + if (use_msi) pci_enable_msi(asd_ha->pcidev); |