Erez Zilber wrote:
> Mike Christie wrote:
>> Erez Zilber wrote:
>>> This new thread summarizes and continues a discussion that we (Mike, Or
>>> and myself) had outside the list. This is what we have so far:
>>>     * Having a parent device: commit
>>>       62786b526687db54c6dc22a1786d6df8b03da3f3 in the bnx2i branch looks
>>>       ok, and will solve the DMA mask problem. I think that it's cleaner
>>>       than calling slave_alloc etc. However, this code cannot be used
>>>       outside the bnx2i branch. I think that we need to create another
>>>       patch (based on this one) to submit upstream. Mike - what do you
>>>       think?
>> I am going to push that code soon. Since it is not critical for 2.6.26 I 
>> am waiting to push it for .27.
> I agree - the DMA mask is not so urgent. However, as you said, Pete is
> waiting with his patch. Do you want to post something in linux-scsi?

Yeah, will do. I ccd him here too, so we could talk about the dma 
alignment patch.

>>>     * iSER alignment issue: I'm not sure if we can force our
>>>       restrictions through scsi_host_template. Again, the restrictions are:
>>>           o The 1st element must end at the page boundary.
>>>           o The last element must start at the page boundary.
>>>           o All other elements must be page aligned (i.e. start at the
>>>             beginning of a page and end at the page boundary).
>>>        Can it be done using blk_queue_dma_alignment? pad_mask?
> I understand that IB's requirements are too difficult to force. I guess
> that we will do something like:
>     * If the scatterlist is aligned, just use it as is.
>     * If some elements at the beginning/end of the scatterlist are
>       unaligned, we can copy only them (and use the rest of the
>       scatterlist as is). We saw that sometimes (e.g. GFS), only the 1st
>       element is unaligned, so copying the whole data is unnecessary.
>     * Else, copy the whole scatterlist to buffers that iSER allocates.
>       This is what we do today with unaligned buffers.

Pete, we are discissing the dma_alignment patch you sent. Above are the 
dma restrictions the iser driver has right now. For the 3rd requirement 
does that mean we want to set the alignment to be page aligned right?

You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To post to this group, send email to
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at

Reply via email to