From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vasily Averin <vvs@sw.ru>
Subject: Re: [SCSI] 3w-9xxx: kmap_atomic in twa_scsiop_execute_scsi
Date: Tue, 06 Jun 2006 23:28:27 +0400
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To: adam radford <aradford@gmail.com>
Cc: Adam Radford <aradford@amcc.com>, linuxraid <linuxraid@amcc.com>, James Bottomley <James.Bottomley@steeleye.com>, linux-scsi@vger.kernel.org, devel@openvz.org, Andrew Morton <akpm@osdl.org>

Adam,

adam radford wrote:
> Vasily,
> 
> On 6/5/06, Vasily Averin <vvs@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