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 the timeout period. If number of retries is 2 or more, the
driver stops sending cmd to FW. IO is resumed when pending cmd count reduces
to 16 or 10 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 accept cmds */
+ if (instance->is_busy) {
+ sec = (jiffies - instance->last_time) / HZ;
+ if (sec < 10)
+ 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
origin.patch
scsi-megaraid_sas-donot-process-cmds-if-hw_crit_error-is-set.patch
scsi-megaraid_sas-added-bios_param-in-scsi_host_template.patch
scsi-megaraid_sas-throttle-io-if-fw-is-busy.patch
scsi-megaraid_sas-replace-pci_alloc_consitent-with-dma_alloc_coherent-in-ioctl-path.patch
scsi-megaraid_sas-return-sync-cache-call-with-success.patch
scsi-megaraid_sas-update-version-and-author-info.patch
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