eh_timed_out call back (megasas_reset_timer) is used to throttle io
to the adapter when it is called the first time for a scmd.
The MEGASAS_FW_BUSY flag is set and can_queue reduced to 16.
The can_queue is restored from completion routine in following
two conditions : 5 seconds has elapsed and
the # of outstanding cmds in FW is < 17.
Signed-off-by: Sumant Patro <sumant.patro@xxxxxxx>
---
drivers/scsi/megaraid/megaraid_sas.c | 67 ++++++++++++++++++++++---
drivers/scsi/megaraid/megaraid_sas.h | 14 +++--
2 files changed, 69 insertions(+), 12 deletions(-)
Re-submitting.
On Thu, 2007-05-10 at 13:23 -0600, James Bottomley wrote:
And the rest of the comments?
This is the cut out of all the ones I made, I think:
> > +static enum
> > +scsi_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
> > +{
> > + struct megasas_cmd *cmd = (struct megasas_cmd *)scmd->SCp.ptr;
> > + struct megasas_instance *instance;
> > + unsigned long flags;
> > +
> > + if (cmd) {
>
> I don't believe we can ever get a command timeout with no command, can
> we?
>
> > + if (time_after(jiffies, scmd->jiffies_at_alloc + 170 *
> HZ))
> > + return EH_NOT_HANDLED;
>
> This 170s is a bit arbitrary ... surely you want it to be related to a
> multiple of scmd->timeout_per_command?
> > + if (!(instance->flag & MEGASAS_FW_BUSY)) {
> > + /* FW is busy, throttle IO */
> > + spin_lock_irqsave(&instance->throttle_io_lock,
> flags);
> > +
> > + instance->host->can_queue = 16;
>
> can_queue is protected by the host lock ... I think you need to dump
> the
> throttle_io_lock and simply use the host lock for all of this.
> > - if (cmd->scmd) {
> > + if (cmd->scmd)
> > cmd->scmd->SCp.ptr = (char *)0;
>
> That's NULL, ordinarily ...
James
diff -uprN orig/drivers/scsi/megaraid/megaraid_sas.c new/drivers/scsi/megaraid/megaraid_sas.c
--- orig/drivers/scsi/megaraid/megaraid_sas.c 2007-05-09 05:32:21.000000000 -0700
+++ new/drivers/scsi/megaraid/megaraid_sas.c 2007-05-17 05:10:24.000000000 -0700
@@ -10,7 +10,7 @@
* 2 of the License, or (at your option) any later version.
*
* FILE : megaraid_sas.c
- * Version : v00.00.03.10-rc1
+ * Version : v00.00.03.10-rc5
*
* Authors:
* (email-id : megaraidlinux@xxxxxxx)
@@ -886,6 +886,7 @@ megasas_queue_command(struct scsi_cmnd *
goto out_return_cmd;
cmd->scmd = scmd;
+ scmd->SCp.ptr = (char *)cmd;
/*
* Issue the command to the FW
@@ -919,7 +920,7 @@ static int megasas_slave_configure(struc
* The RAID firmware may require extended timeouts.
*/
if (sdev->channel >= MEGASAS_MAX_PD_CHANNELS)
- sdev->timeout = 90 * HZ;
+ sdev->timeout = MEGASAS_DEFAULT_CMD_TIMEOUT * HZ;
return 0;
}
@@ -981,8 +982,8 @@ static int megasas_generic_reset(struct
instance = (struct megasas_instance *)scmd->device->host->hostdata;
- scmd_printk(KERN_NOTICE, scmd, "megasas: RESET -%ld cmd=%x\n",
- scmd->serial_number, scmd->cmnd[0]);
+ scmd_printk(KERN_NOTICE, scmd, "megasas: RESET -%ld cmd=%x retries=%x\n",
+ scmd->serial_number, scmd->cmnd[0], scmd->retries);
if (instance->hw_crit_error) {
printk(KERN_ERR "megasas: cannot recover from previous reset "
@@ -1000,6 +1001,39 @@ static int megasas_generic_reset(struct
}
/**
+ * megasas_reset_timer - quiesce the adapter if required
+ * @scmd: scsi cmnd
+ *
+ * Sets the FW busy flag and reduces the host->can_queue if the
+ * cmd has not been completed within the timeout period.
+ */
+static enum
+scsi_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
+{
+ struct megasas_cmd *cmd = (struct megasas_cmd *)scmd->SCp.ptr;
+ struct megasas_instance *instance;
+ unsigned long flags;
+
+ if (time_after(jiffies, scmd->jiffies_at_alloc +
+ (MEGASAS_DEFAULT_CMD_TIMEOUT * 2) * HZ)) {
+ return EH_NOT_HANDLED;
+ }
+
+ instance = cmd->instance;
+ if (!(instance->flag & MEGASAS_FW_BUSY)) {
+ /* FW is busy, throttle IO */
+ spin_lock_irqsave(instance->host->host_lock, flags);
+
+ instance->host->can_queue = 16;
+ instance->last_time = jiffies;
+ instance->flag |= MEGASAS_FW_BUSY;
+
+ spin_unlock_irqrestore(instance->host->host_lock, flags);
+ }
+ return EH_RESET_TIMER;
+}
+
+/**
* megasas_reset_device - Device reset handler entry point
*/
static int megasas_reset_device(struct scsi_cmnd *scmd)
@@ -1112,6 +1146,7 @@ static struct scsi_host_template megasas
.eh_device_reset_handler = megasas_reset_device,
.eh_bus_reset_handler = megasas_reset_bus_host,
.eh_host_reset_handler = megasas_reset_bus_host,
+ .eh_timed_out = megasas_reset_timer,
.bios_param = megasas_bios_param,
.use_clustering = ENABLE_CLUSTERING,
};
@@ -1215,9 +1250,8 @@ megasas_complete_cmd(struct megasas_inst
int exception = 0;
struct megasas_header *hdr = &cmd->frame->hdr;
- if (cmd->scmd) {
- cmd->scmd->SCp.ptr = (char *)0;
- }
+ if (cmd->scmd)
+ cmd->scmd->SCp.ptr = NULL;
switch (hdr->cmd) {
@@ -1806,6 +1840,7 @@ static void megasas_complete_cmd_dpc(uns
u32 context;
struct megasas_cmd *cmd;
struct megasas_instance *instance = (struct megasas_instance *)instance_addr;
+ unsigned long flags;
/* If we have already declared adapter dead, donot complete cmds */
if (instance->hw_crit_error)
@@ -1828,6 +1863,22 @@ static void megasas_complete_cmd_dpc(uns
}
*instance->consumer = producer;
+
+ /*
+ * Check if we can restore can_queue
+ */
+ if (instance->flag & MEGASAS_FW_BUSY
+ && time_after(jiffies, instance->last_time + 5 * HZ)
+ && atomic_read(&instance->fw_outstanding) < 17) {
+
+ spin_lock_irqsave(instance->host->host_lock, flags);
+ instance->flag &= ~MEGASAS_FW_BUSY;
+ instance->host->can_queue =
+ instance->max_fw_cmds - MEGASAS_INT_CMDS;
+
+ spin_unlock_irqrestore(instance->host->host_lock, flags);
+ }
+
}
/**
@@ -2398,6 +2449,8 @@ megasas_probe_one(struct pci_dev *pdev,
instance->init_id = MEGASAS_DEFAULT_INIT_ID;
megasas_dbg_lvl = 0;
+ instance->flag = 0;
+ instance->last_time = 0;
/*
* Initialize MFI Firmware
diff -uprN orig/drivers/scsi/megaraid/megaraid_sas.h new/drivers/scsi/megaraid/megaraid_sas.h
--- orig/drivers/scsi/megaraid/megaraid_sas.h 2007-05-09 05:32:21.000000000 -0700
+++ new/drivers/scsi/megaraid/megaraid_sas.h 2007-05-17 05:00:51.000000000 -0700
@@ -18,9 +18,9 @@
/*
* MegaRAID SAS Driver meta data
*/
-#define MEGASAS_VERSION "00.00.03.10-rc1"
-#define MEGASAS_RELDATE "Feb 14, 2007"
-#define MEGASAS_EXT_VERSION "Wed Feb 14 10:14:25 PST 2007"
+#define MEGASAS_VERSION "00.00.03.10-rc5"
+#define MEGASAS_RELDATE "May 17, 2007"
+#define MEGASAS_EXT_VERSION "Thu May 17 10:09:32 PDT 2007"
/*
* Device IDs
@@ -539,6 +539,8 @@ struct megasas_ctrl_info {
#define MEGASAS_DBG_LVL 1
+#define MEGASAS_FW_BUSY 1
+
/*
* When SCSI mid-layer calls driver's reset routine, driver waits for
* MEGASAS_RESET_WAIT_TIME seconds for all outstanding IO to complete. Note
@@ -549,8 +551,8 @@ struct megasas_ctrl_info {
#define MEGASAS_RESET_WAIT_TIME 180
#define MEGASAS_INTERNAL_CMD_WAIT_TIME 180
#define MEGASAS_RESET_NOTICE_INTERVAL 5
-
#define MEGASAS_IOCTL_CMD 0
+#define MEGASAS_DEFAULT_CMD_TIMEOUT 90
/*
* FW reports the maximum of number of commands that it can accept (maximum
@@ -1073,7 +1075,6 @@ struct megasas_instance {
struct megasas_register_set __iomem *reg_set;
s8 init_id;
- u8 reserved[3];
u16 max_num_sge;
u16 max_fw_cmds;
@@ -1104,6 +1105,9 @@ struct megasas_instance {
struct megasas_instance_template *instancet;
struct tasklet_struct isr_tasklet;
+
+ u8 flag;
+ unsigned long last_time;
};
#define MEGASAS_IS_LOGICAL(scp) \
-
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