From f19eaa7f53736449a6eac89c3863eca2c64d5913 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" <djwong@us.ibm.com> Date: Wed, 30 Aug 2006 14:18:33 -0700 Subject: [PATCH] [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> --- drivers/scsi/aic94xx/aic94xx_init.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c index 3ec2e46f80c61e..69aa7088753029 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); -- GitLab