>>>>> "Robert" == Robert Hancock <[email protected]> writes:

>> Did I miss something to make the block layer generate bigger size
>> data for every request in the request queue?  Below is part of my
>> source code. Any comments are highly appreciated. Thank you in
>> advance.

Robert> 8 sectors is 4KB, that's the size of a page. If the pages that
Robert> are being written are not physically contiguous that may be the
Robert> best the block layer can do with the constraints you've given it
Robert> (not supporting any more than 1 DMA segment). 

Correct.  It's quite unlikely for pages to be contiguous so this is the
best we can do.

Having recently done a cleanup of our segment handling I became aware
that there are many MMC devices that are single-element only.  This was
probably a sufficient approach for 32MB devices but it's time to get
with the program and implement proper scatter-gather.

-- 
Martin K. Petersen      Oracle Linux Engineering
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to