[393] in linux-scsi channel archive
Re: Reading more than buffersize
daemon@ATHENA.MIT.EDU (Eric Youngdale)
Tue Jul 18 07:16:42 1995
Date: Tue, 18 Jul 95 00:53 EDT
From: eric@aib.com (Eric Youngdale)
To: Drew Eckhardt <drew@poohsticks.org>
CC: mucci@cs.utk.edu, linux-scsi@vger.rutgers.edu
>One difficult bit is maintaining synchronicity with the buffer
>cache in a way that's compatable with performance. If you do a single
>direct read/write, it would probably be optimal to just set your pages
>to COW and give them a context in the buffer cache as wll.
This talk of 0-copy block devices makes me wonder whether the
correct place to implement something like this would be in the
filesystem rather than the device driver. It would amount to a special
case for large reads/writes (for small read/writes it would be pointless
to try 0-copy, since you would have to copy more data around to get the
end bits set properly.
-Eric
