Re: sata_mv, io stucks

[Mark Lord <liml@rtr.ca>]

Harri Olin wrote:
..
>>>>>> Two marvell controllers, 16 disks, software raid10, IO stucks on 
>>>>>> different disks, kernel 2.6.26.5.
>>>>>> With default ubuntu's 8.04 2.6.24 kernel the problem can not be 
>>>>>> repeated
>>>>>>
>>>>>>
>>>>>> [  289.851609] ata11.00: exception Emask 0x0 SAct 0x1 SErr 0x0 
>>>>>> action 0x6 frozen
>>>>>> [  289.851695] ata11.00: cmd 61/08:00:60:1e:bf/00:00:01:00:00/40 
>>>>>> tag 0 ncq 4096 out
>>>>>> [  289.851697]          res 40/00:00:00:00:00/00:00:00:00:00/00 
>>>>>> Emask 0x4 (timeout)
>>>>>> [  289.851774] ata11.00: status: { DRDY }
>>>>>> [  289.851834] ata11: hard resetting link
>>>>>> [  290.649259] ata11: SATA link up 3.0 Gbps (SStatus 123 SControl 
>>>>>> 300)
>>>>>> [  290.749239] ata11.00: max_sectors limited to 256 for NCQ
>>>>>> [  290.809189] ata11.00: max_sectors limited to 256 for NCQ
>>>>>> [  290.809194] ata11.00: configured for UDMA/133
>>>>>> [  290.809200] ata11: EH complete
>>>>>> [  290.809242] sd 10:0:0:0: [sdk] 1953525168 512-byte hardware 
>>>>>> sectors (1000205 MB)
>>>>>> [  290.809258] sd 10:0:0:0: [sdk] Write Protect is off
>>>>>> [  290.809263] sd 10:0:0:0: [sdk] Mode Sense: 00 3a 00 00
>>>>>> [  290.809286] sd 10:0:0:0: [sdk] Write cache: enabled, read 
>>>>>> cache: enabled, doesn't support DPO or FUA
..
> I have to take back that bisect, as just couple of minutes ago it 
> happened again, with last 'good' kernel from bisect. Just the frequency 
> of stalls has dropped quite much. I also noticed that on current kernels 
> are much better too.
> pre-..0ff7efa8c: only once after 6 hours of testing
> post-..0ff7efa8c: one hd stalled while filesystem was mounting. Before 
> boot was complete, 3 stalls. Also at shutdown kernel hung at 
> Synchronizing SCSI cache for a while.
> 2.6.27: once in 5 minutes or so on heavy load
> 
> When some hd/port stalls, other ports sill work fine.
> 
> I applied your patch on 2.6.27.1, no results:
> 
> ata14.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x6 frozen
> ata14.00: cmd 61/08:00:3f:52:54/00:00:57:00:00/40 tag 0 ncq 4096 out
>         res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
..

Yeah, I see what I was missing earlier:   "(timeout)".
So it's "none of" the driver paths.

This could very well be due to one/several of the as-yet un-addressed
chipset errata for the 6081.  Someday we'll have software workarounds
for those, but I'm (still) waiting on Marvell for stuff.

I will look and see if this makes sense based on the errata info
that I have already though (under NDA).

Harri / Artem:  what type/speed of slots are your 6081 controllers in?
PCI, or PCI-X?   Bus speed?

Thanks