[PATCH 4.17 11/56] scsi: aacraid: Fix PD performance regression over incorrect qd being set

From: Greg Kroah-Hartman
Date: Tue Jul 10 2018 - 14:34:31 EST


4.17-stable review patch. If anyone has any objections, please let me know.

------------------

From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@xxxxxxxxxxxxx>

commit 59b433c825569ce251371485f0e29fca888b549d upstream.

The driver fails to set the correct queue depth for native devices, due to
failing to set the device type prior to calling aac_set_safw_target_qd().
This results in slave configure setting the queue depth to 1.

This causes around 30% performance degradation. Fixed by setting the dev
type before trying to set queue depth.

Reported-by: Steve Best <sbest@xxxxxxxxxx>
Fixes: 0bcb45fb20c21 ("scsi: aacraid: Add helper function to set queue depth")
cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@xxxxxxxxxxxxx>
Reviewed-by: David Carroll <David.Carroll@xxxxxxxxxxxxx>
Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/aacraid/aachba.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -1974,7 +1974,6 @@ static void aac_set_safw_attr_all_target
u32 lun_count, nexus;
u32 i, bus, target;
u8 expose_flag, attribs;
- u8 devtype;

lun_count = aac_get_safw_phys_lun_count(dev);

@@ -1992,23 +1991,23 @@ static void aac_set_safw_attr_all_target
continue;

if (expose_flag != 0) {
- devtype = AAC_DEVTYPE_RAID_MEMBER;
- goto update_devtype;
+ dev->hba_map[bus][target].devtype =
+ AAC_DEVTYPE_RAID_MEMBER;
+ continue;
}

if (nexus != 0 && (attribs & 8)) {
- devtype = AAC_DEVTYPE_NATIVE_RAW;
+ dev->hba_map[bus][target].devtype =
+ AAC_DEVTYPE_NATIVE_RAW;
dev->hba_map[bus][target].rmw_nexus =
nexus;
} else
- devtype = AAC_DEVTYPE_ARC_RAW;
+ dev->hba_map[bus][target].devtype =
+ AAC_DEVTYPE_ARC_RAW;

dev->hba_map[bus][target].scan_counter = dev->scan_counter;

aac_set_safw_target_qd(dev, bus, target);
-
-update_devtype:
- dev->hba_map[bus][target].devtype = devtype;
}
}