Re: [PATCHSET] block: fix PIO cache coherency bug, take 2

[Russell King]

On Mon, Jun 05, 2006 at 10:24:44AM -0500, James Bottomley wrote:
> On Mon, 2006-06-05 at 15:44 +0100, Russell King wrote:
> > Hence I find your comment "There are two cases where devices kmap a
> > user page into kernel space and then proceed to read from or write to
> > it" to be misleading - at the exact point in time that the device
> > driver is manipulating the data in that page, it is not a user page.
> 
> zero copy doesn't quite follow that ownership model.

What has zero copy (your reply) got to do with faulting pages into
userspace (my message).  I'm sorry, I don't understand why you've
brought this up.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core
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