Re: RFC: ATA to CAM integration patch (INTEL DX58SO)

At 03:31 PM 7/3/2009, Alexander Motin wrote:
>It would be more interesting to investigate benefits on NCQ suitable 
>workload, as that are new for us. Something like unpacking a lot of 
>small files to normal or async-mounted or gjournalled FS, or some 
>multi-threaded read, or something else. Would be nice to understand 
>on which types of workload NCQ could give us visible effects.
>
>You can track real requests parallelism by looking on dev_active 
>field of `camcontrol tags ada0 -v`.


We dont have too many disk I/O bound apps here.  Where we do, we 
typically have used raid controllers in RAID10.  But I will 
experiment a little more over the weekend.  For us, we are interested 
in large amounts of storage for backup purposes.  Having things like 
port multiplier features are very nice to have.  But I will try some 
random io tests to see if I can measure a difference.


>>The eSata port does not work, but it never did under the old driver 
>>either. I think it has a separate controller ?  At the BIOS boot up 
>>time, it shows some Marvell controller talking to the eSata 
>>attached drive, and pciconf does show a separate ATA controller


>>atapci0_at_pci0:6:0:0:     class=0x01018f card=0x4f538086 
>>chip=0x612111ab rev=0xb2 hdr=0x00
>>     vendor     = 'Marvell Semiconductor (Was: Galileo Technology Ltd)'
>>     device     = '6121 SATA2 Controller'
>>     class      = mass storage
>>     subclass   = ATA
>>     cap 01[48] = powerspec 2  supports D0 D1 D3  current D0
>>     cap 05[50] = MSI supports 1 message
>>     cap 10[e0] = PCI-Express 1 legacy endpoint max data 128(128) link x1(x1)
>
>But this device, implementing both PATA and SATA ports, report 
>itself as PATA controller. It's SATA part may be AHCI compatible, 
>but driver unable to attach it due to incorrect device 
>identification. Alike happens to my JMicron controllers, but in that 
>case system BIOS is able to switch it into the right mode with 
>separate PATA and AHCI SATA controllers devices.

Looking in the BIOS, I am able to toggle IDE and RAID mode only for 
the eSata controller portion, where as I have IDE, AHCI and RAID for 
the onboard Intel controller.

         ---Mike