bus dma: a flag/quirk for page zero

John Baldwin jhb at freebsd.org
Thu Jan 12 12:35:39 UTC 2012

On Wednesday, January 11, 2012 2:56:47 pm Andriy Gapon wrote:
> on 11/01/2012 19:18 Andriy Gapon said the following:
> > Actually, I think that on x86 we don't have to do anything special for any memory
> > allocations that we do, including the bounce pages, as the page zero is excluded
> > from phys_avail and is not available for normal use.
> After some additional thinking there is probably no reason to take advantage of
> this fact.  First, it would increase differences with other platforms.  Second,
> it would add a hidden dependency.  So it's better to be explicit here.


John Baldwin

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