Scott Long wrote:
> On Apr 29, 2010, at 10:56 PM, Alexander Motin wrote:
>> Scott Long wrote:
>>> On Apr 29, 2010, at 7:47 AM, Robert Noland wrote:
>>>> Scott Long wrote:
>>>>> On Apr 29, 2010, at 2:50 AM, Pete French wrote:
>>>>>>> Thanks. First step successful - I can steadily reproduce problem on
>>>>>>> CURRENT. raidtest with 200 I/O streams over gmirror of two disks on same
>>>>>>> channel triggers issue in seconds. Any I/O on channel dying after both
>>>>>>> disks report "Queue full" error same time. The rest of system works
>>>>>>> fine. If I preliminarily manually adjust queue depth of one disk -
>>>>>>> everything works fine. I'll investigate it tomorrow.
>>>>>> Glad you have managed to dupliate it - the queue depth thing is
>>>>>> inetersting, what changes did you make ? I can try them here and see
>>>>>> if they improve the situation on either of my two machines.
>>>>>>
>>>>> For the record, queue-full is a common, expected condition in CAM.  It's 
>>>>> not something that should be avoided =-)
>>>> Should we maybe have a counter in sysctl rather than flooding the console 
>>>> with these messages then?
>>> That's a pretty good idea.  I'll make it happen.
>> It is already hidden behind bootverbose. Hiding it deeper will make
>> unclear why CAM requeues the rest of commands (also reported under
>> bootverbose). I've tuned log messages a bit recently and they seem to be
>> more consistent and readable now IMHO.
> 
> We used to run FreeBSD at Yahoo with bootverbose turned on in order to help 
> with debugging.  After years of doing this, I finally turned bootverbose off 
> last year, partially because of the excessive console spam produced by these 
> queue-full messages.  Even when we were writing the ahc/ahd drivers at 
> Adaptec years ago, I never really liked these messages, and we rarely ran 
> with bootverbose turned on unless we were actively developing code or 
> debugging a problem.  I like Robert's suggestion because not only does it 
> make running with bootverbose less painful, it can also provide counters and 
> also calculate and report rate measurements that might be more useful than 
> just the printf.
> 
> If you feel strongly against it, I won't push it, but I do like the 
> suggestion.

No. I just wanted to say that requeue messages massively logged in that
case are even less informative for regular user.

-- 
Alexander Motin
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