User allocated memory for DMA

Benjamin Herrenschmidt benh at
Tue Dec 7 18:09:48 EST 2004

On Mon, 2004-12-06 at 18:29 +0530, Amit K Tiwari wrote:

> My problem is that at step 3 I do not get any contiguous region.
> Surprisingly, some of the physical addresses are such that the low
> order page (say page 151) has high order physical address (say,
> 1ef234000) while the next high order page (say page 152) has the next
> lower physical address(say 1ef233000) and this trend continues for
> some 10 pages after which the addresses totally far apart.

What kernel version is this ? I remember something about the default
allocation "direction" of pages beeing changed a while ago...


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