megaraid_sas: Dual queue depth support
1. For iMR controllers, firmware will report two queue depths:
- Controller-wide queue depth
- LDIO queue depth (240)
Controller-wide queue depth will be greater among the two. Using this
new feature, iMR can provide larger Queue depth(QD) for JBOD and limited
QD for Virtual Disk(VD).
2. megaraid_sas driver will throttle read/write LDIOs based on "LDIO
Queue Depth".
3. Dual queue depth can be enabled/disabled via module parameter. It is
enabled by default if the firmware supports it. Only specific firmware
builds will enable the feature.
4. Added sysfs parameter "ldio_outstanding" which permits querying the
number of outstanding LDIO requests at runtime.
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index edf8911..961c024 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -96,6 +96,10 @@
module_param(rdpq_enable, int, S_IRUGO);
MODULE_PARM_DESC(rdpq_enable, " Allocate reply queue in chunks for large queue depth enable/disable Default: disable(0)");
+unsigned int dual_qdepth_disable;
+module_param(dual_qdepth_disable, int, S_IRUGO);
+MODULE_PARM_DESC(dual_qdepth_disable, "Disable dual queue depth feature. Default: 0");
+
MODULE_LICENSE("GPL");
MODULE_VERSION(MEGASAS_VERSION);
MODULE_AUTHOR("megaraidlinux.pdl@avagotech.com");
@@ -1976,7 +1980,7 @@
spin_lock_irqsave(instance->host->host_lock, flags);
instance->flag &= ~MEGASAS_FW_BUSY;
- instance->host->can_queue = instance->max_scsi_cmds;
+ instance->host->can_queue = instance->cur_can_queue;
spin_unlock_irqrestore(instance->host->host_lock, flags);
}
}
@@ -2941,6 +2945,16 @@
return snprintf(buf, PAGE_SIZE, "%ld\n", (unsigned long)PAGE_SIZE - 1);
}
+static ssize_t
+megasas_ldio_outstanding_show(struct device *cdev, struct device_attribute *attr,
+ char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(cdev);
+ struct megasas_instance *instance = (struct megasas_instance *)shost->hostdata;
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&instance->ldio_outstanding));
+}
+
static DEVICE_ATTR(fw_crash_buffer, S_IRUGO | S_IWUSR,
megasas_fw_crash_buffer_show, megasas_fw_crash_buffer_store);
static DEVICE_ATTR(fw_crash_buffer_size, S_IRUGO,
@@ -2949,12 +2963,15 @@
megasas_fw_crash_state_show, megasas_fw_crash_state_store);
static DEVICE_ATTR(page_size, S_IRUGO,
megasas_page_size_show, NULL);
+static DEVICE_ATTR(ldio_outstanding, S_IRUGO,
+ megasas_ldio_outstanding_show, NULL);
struct device_attribute *megaraid_host_attrs[] = {
&dev_attr_fw_crash_buffer_size,
&dev_attr_fw_crash_buffer,
&dev_attr_fw_crash_state,
&dev_attr_page_size,
+ &dev_attr_ldio_outstanding,
NULL,
};
@@ -4749,6 +4766,7 @@
sema_init(&instance->ioctl_sem, (MEGASAS_MFI_IOCTL_CMDS));
}
+ instance->cur_can_queue = instance->max_scsi_cmds;
/*
* Create a pool of commands
*/