From 05e9ebbefb379a4da782b21b8427c88ac28a2334 Mon Sep 17 00:00:00 2001 From: Sumant Patro Date: Thu, 17 May 2007 05:47:51 -0700 Subject: [SCSI] megaraid_sas: intercept cmd timeout and throttle io 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 Signed-off-by: James Bottomley --- drivers/scsi/megaraid/megaraid_sas.c | 67 ++++++++++++++++++++++++++++++++---- 1 file changed, 60 insertions(+), 7 deletions(-) (limited to 'drivers/scsi/megaraid/megaraid_sas.c') diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c index 7a812677ff8..e2cf12ef368 100644 --- a/drivers/scsi/megaraid/megaraid_sas.c +++ b/drivers/scsi/megaraid/megaraid_sas.c @@ -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@lsi.com) @@ -886,6 +886,7 @@ megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (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(struct scsi_device *sdev) * 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 scsi_cmnd *scmd) 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 " @@ -999,6 +1000,39 @@ static int megasas_generic_reset(struct scsi_cmnd *scmd) return ret_val; } +/** + * 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 */ @@ -1112,6 +1146,7 @@ static struct scsi_host_template megasas_template = { .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_instance *instance, struct megasas_cmd *cmd, 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(unsigned long instance_addr) 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(unsigned long instance_addr) } *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, const struct pci_device_id *id) instance->init_id = MEGASAS_DEFAULT_INIT_ID; megasas_dbg_lvl = 0; + instance->flag = 0; + instance->last_time = 0; /* * Initialize MFI Firmware -- cgit v1.2.3