Re: [PATCH 0/1] scsi: Handle MLQUEUE busy response in scsi_send_eh_cmnd

[Brian King <brking@linux.vnet.ibm.com>]

On 04/15/2013 05:33 PM, James Bottomley wrote:
> On Mon, 2013-04-15 at 16:55 -0500, Brian King wrote:
>> On 04/15/2013 03:45 PM, James Bottomley wrote:
>>> On Mon, 2013-04-15 at 13:39 -0500, wenxiong@linux.vnet.ibm.com wrote:
>>>> In scsi_send_eh_cmnd(), this fix will check the return code of queuecomamnd
>>>> when sending commands and retry for a bit if the driver returns a
>>>> busy response.
>>>
>>> This is already handled by the timeout, I think.  If a driver
>>> continuously returns MLQUEUE BUSY, then we'll fail the request after the
>>> timeout on the command expires.
>>
>> If we get a timeout in scsi_send_eh_cmnd we call scsi_abort_eh_cmnd. If the
>> abort works, we return FAILED out of scsi_send_eh_cmnd, which results in
>> no retry being performed, since scsi_eh_tur only retries once and
>> only if NEEDS_RETRY is returned. Or am I missing something?
> 
> Sorry, I'm not being clear.  It comes with being at a conference.  What
> I mean is that if you do this, the criterion for success or failure
> should be the amount of time left not the number of retries.  This is
> what the non-eh submission path also does for retries of events that
> don't count against the retry limit ... so something like this patch
> (uncompiled and untested #include stddisclaimer.h)

Jams,

Wendy and I discussed this a bit more and I think we understand your concern.
Wendy is working on an updated patch.

Thanks,

Brian

-- 
Brian King
Power Linux I/O
IBM Linux Technology Center