Thank you James. I will submit new patch that will throttle (if required) from eh_timed_out call back. Regards, Sumant -----Original Message----- From: James Bottomley [mailto:James.Bottomley@xxxxxxxxxxxx] Sent: Friday, March 16, 2007 3:23 PM To: Patro, Sumant Cc: akpm@xxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Kolli, Neela; Yang, Bo Subject: Re: [PATCH] scsi: megaraid_sas - throttle io if cmds are in riskof being timed-out On Thu, 2007-03-01 at 13:29 -0800, Sumant Patro wrote: > Driver to throttle IO to reduce risk of OS timing out cmds. > > Implemented a circular queue to keep track of pending OS cmds in FW. > This queue is periodically (every 10 sec) checked by a timer routine. > If there is any cmd that is in risk of getting timed-out by the OS, > the host->can_queue is reduced to 16 and MEGASAS_FW_BUSY flag is set. > The host->can_queue will be restored to default value when the > following two conditions are met : 5 secs has elapsed and the # of > outstanding cmds in FW is less than 17. > Also increased the per cmd timeout to 120*HZ from 90*HZ. OK, this is still not nice. What you need to be doing is intercepting the timeout before it fires (and quiesces the machine). Currently the eh_timed_out() callback is only exposed to transport classes, I'll put it back into the host template and then you can use it. James - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
