cvs commit: src/sys/dev/ata ata-all.h ata-chipset.c ata-dma.c ata-pci.c ata-pci.h atapi-cd.c atapi-fd.c atapi-tape.c

[Maxim Sobolev]

Robert Watson wrote:
> On Thu, 22 Nov 2007, Søren Schmidt wrote:
> 
>>>>>   FreeBSD src repository
>>>>>
>>>>>   Modified files:  (Branch: RELENG_7)
>>>>>     sys/dev/ata ata-all.h ata-chipset.c ata-dma.c ata-pci.c 
>>>>> ata-pci.h atapi-cd.c atapi-fd.c atapi-tape.c Log:
>>>>>   Update with the latest fixes from -current.
>>>>
>>>> Please don't forget to merge at least atapi-cd.c fix into RELENG_6. 
>>>> Currently CD is not working in Parallels with 6.3-PRERELEASE.
>>>
>>> Also, I see some "ad0: TIMEOUT - WRITE_DMA (retrying)" messages with 
>>> Parallels using latest 6.3-PRERELEASE snapshot. Not sure if it's due 
>>> to some changes between 6.2 and 6.3, but I've never seen this with 
>>> 6.2. Any ideas?
>>
>> I have a complete backport of all the latest fixes done for 6.3 
>> awaiting approval.
>>
>> I've seen such a timeout once on 6.3 before I merged the latest 
>> changes, since then I've not seen any, not that it means much though :)
> 
> I see them any time I do anything involving significant disk load under 
> Parallels--I've always assumed it was because there are several layers 
> of indirection, including HFS+ and an expanding Parallels disk image, 
> beween the FreeBSD ATA driver and hardware, leading to significantly 
> longer delays than the ATA driver would expect from normal hardware.  
> That said, I'm fine with being wrong and seeing a bug fixed :-).  I 
> usually get several each time I buildkernel, such as last night:
> 
> ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=5208191
> ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=23670111
> ad0: TIMEOUT - READ_DMA retrying (1 retry left) LBA=5843715
> ad0: TIMEOUT - WRITE_DMA retrying (1 retry left) LBA=40407615

Assuming that there are no actual bugs in the code, should not it make 
sense to detect virtual hardware and treat it a little bit differently 
with respect to timeouts? Given the growing popularity of virtualization 
technology it's doesn't sound like a worthless project.

-Maxim