On Wed, Jul 04, 2001 at 20:18:51 -0400, Kevin Hui wrote:
> Then the question is whether the kernel is copying data between userspace
> and kernelspace or whether it just DMAs the data straight in/out of the
> user program's address space. In Linux raw-io, given that it is a block
> device and you are doing page-aligned block I/Os on it, is smart and does
> zero copies. While it may seem to be jumping through hoops, maybe it does
> have a performance advantage?
The kernel copies between userland and the kernel.
Ken
--
Kenneth Merry
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