scsi: megaraid_sas: add correct return type check for ldio hint logic for raid1
authorShivasharan S <shivasharan.srikanteshwara@broadcom.com>
Fri, 10 Mar 2017 11:22:13 +0000 (03:22 -0800)
committerMartin K. Petersen <martin.petersen@oracle.com>
Tue, 14 Mar 2017 02:59:53 +0000 (22:59 -0400)
Return value check of atomic_dec_if_positive is required as it returns
old value minus one.  Without this fix, driver will send small ios to
firmware path and that will be a performance issue.

Not critical, but good to have r1_ldio_hint as default value in sdev
private.

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/megaraid/megaraid_sas_base.c
drivers/scsi/megaraid/megaraid_sas_fusion.c

index 016ffce..0016f12 100644 (file)
@@ -1963,6 +1963,9 @@ scan_target:
        if (!mr_device_priv_data)
                return -ENOMEM;
        sdev->hostdata = mr_device_priv_data;
+
+       atomic_set(&mr_device_priv_data->r1_ldio_hint,
+                  instance->r1_ldio_hint_default);
        return 0;
 }
 
index 29650ba..ebd746e 100644 (file)
@@ -2338,7 +2338,7 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
                                fp_possible = false;
                                atomic_dec(&instance->fw_outstanding);
                        } else if ((scsi_buff_len > MR_LARGE_IO_MIN_SIZE) ||
-                                  atomic_dec_if_positive(&mrdev_priv->r1_ldio_hint)) {
+                                  (atomic_dec_if_positive(&mrdev_priv->r1_ldio_hint) > 0)) {
                                fp_possible = false;
                                atomic_dec(&instance->fw_outstanding);
                                if (scsi_buff_len > MR_LARGE_IO_MIN_SIZE)