The patch titled
scsi: megaraid_sas - throttle io if FW is busy
has been added to the -mm tree. Its filename is
scsi-megaraid_sas-throttle-io-if-fw-is-busy.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: scsi: megaraid_sas - throttle io if FW is busy
From: Sumant Patro <sumantp@xxxxxxxx>
Checks added in megasas_queue_command to know if FW is able to process
commands within timeout period. If number of retries is 2 or greater, the
driver stops sending cmd to FW. IO is resumed if pending cmd count reduces to
16 or 5 seconds has elapsed from the time cmds were last sent to FW.
Signed-off-by: Sumant Patro <sumant.patro@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/megaraid/megaraid_sas.c | 27 +++++++++++++++++++++++++
drivers/scsi/megaraid/megaraid_sas.h | 3 ++
2 files changed, 30 insertions(+)
diff -puN drivers/scsi/megaraid/megaraid_sas.c~scsi-megaraid_sas-throttle-io-if-fw-is-busy drivers/scsi/megaraid/megaraid_sas.c
--- a/drivers/scsi/megaraid/megaraid_sas.c~scsi-megaraid_sas-throttle-io-if-fw-is-busy
+++ a/drivers/scsi/megaraid/megaraid_sas.c
@@ -839,6 +839,7 @@ megasas_queue_command(struct scsi_cmnd *
u32 frame_count;
struct megasas_cmd *cmd;
struct megasas_instance *instance;
+ unsigned long sec;
instance = (struct megasas_instance *)
scmd->device->host->hostdata;
@@ -856,6 +857,23 @@ megasas_queue_command(struct scsi_cmnd *
goto out_done;
}
+ /* Check if we can process cmds */
+ if(instance->is_busy){
+ sec = (jiffies - instance->last_time) / HZ;
+ if(sec<5)
+ return SCSI_MLQUEUE_HOST_BUSY;
+ else{
+ instance->is_busy=0;
+ instance->last_time=0;
+ }
+ }
+
+ if(scmd->retries>1){
+ /* FW is busy */
+ instance->is_busy=1;
+ instance->last_time=jiffies;
+ }
+
cmd = megasas_get_cmd(instance);
if (!cmd)
return SCSI_MLQUEUE_HOST_BUSY;
@@ -1200,6 +1218,7 @@ megasas_complete_cmd(struct megasas_inst
{
int exception = 0;
struct megasas_header *hdr = &cmd->frame->hdr;
+ int outstanding;
if (cmd->scmd) {
cmd->scmd->SCp.ptr = (char *)0;
@@ -1313,6 +1332,12 @@ megasas_complete_cmd(struct megasas_inst
hdr->cmd);
break;
}
+
+ if(instance->is_busy){
+ outstanding = atomic_read(&instance->fw_outstanding);
+ if(outstanding<17)
+ instance->is_busy=0;
+ }
}
/**
@@ -2384,6 +2409,8 @@ megasas_probe_one(struct pci_dev *pdev,
instance->init_id = MEGASAS_DEFAULT_INIT_ID;
megasas_dbg_lvl = 0;
+ instance->is_busy = 0;
+ instance->last_time = 0;
/*
* Initialize MFI Firmware
diff -puN drivers/scsi/megaraid/megaraid_sas.h~scsi-megaraid_sas-throttle-io-if-fw-is-busy drivers/scsi/megaraid/megaraid_sas.h
--- a/drivers/scsi/megaraid/megaraid_sas.h~scsi-megaraid_sas-throttle-io-if-fw-is-busy
+++ a/drivers/scsi/megaraid/megaraid_sas.h
@@ -1102,6 +1102,9 @@ struct megasas_instance {
atomic_t fw_outstanding;
u32 hw_crit_error;
+ u8 is_busy;
+ unsigned long last_time;
+
struct megasas_instance_template *instancet;
struct tasklet_struct isr_tasklet;
};
_
Patches currently in -mm which might be from sumantp@xxxxxxxx are
git-scsi-misc.patch
scsi-megaraid_sas-stop-cmd-processing-if.patch
scsi-megaraid_sas-added-bios_param-in.patch
scsi-megaraid_sas-throttle-io-if-fw-is-busy.patch
scsi-megaraid_sas-preallocate-memory-for-ioctl.patch
scsi-megaraid_sas-update-version-and-author-info.patch
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