[Devel] Re: [SCSI] 3w-9xxx: kmap_atomic in twa_scsiop_execute_scsi

[Vasily Averin]

Adam,

adam radford wrote:
> Vasily,
> 
> On 6/5/06, Vasily Averin <vvs at sw.ru> wrote:
> 
>> I'm agree that queuecommand() executed with disabled interrupts. However
>> twa_scsiop_execute_scsi() can be called not only from queuecommand.
>> For example,
>>
>> twa_interrupts (note: with _enabled_ interrupts)
>>    twa_aen_read_queue
>>      twa_scsiop_execute_scsi
>>
> 
> twa_scsiop_execute_scsi() will not perform the
> kmap_atomic()/kunmap_atomic()
> calls here because it is being used for an internal AEN drain  (cdb
> post), i.e. "sglistarg" is non NULL.  See below:
> 
> if (!sglistarg) {
> 
>  ....
>   kmap_atomc()
>   kunmap_atomic()
> 
> } else {
>   /* Internal cdb post */
> 
> }

Ok, I'm agree.

Thank you for your explanation,
	Vasily Averin

SWsoft Virtuozzo/OpenVZ Linux kernel team