Re: [PATCH 04/11] unpaged: unifdefed PageCompound

David S. Miller
2005-11-19T21:45:15Z

From: William Lee Irwin III <wli@holomorphy.com>
Date: Sat, 19 Nov 2005 12:55:57 -0800

> On Thu, 17 Nov 2005, David S. Miller wrote:
> >> I think this is a good change regardless of the VM_RESERVED issues.
> >> I've been wanting to use this facility in some sparc64 bits in
> >> the past, for example. But since it was HUGETLB guarded that
> >> wasn't possible.
>
> On Sat, Nov 19, 2005 at 08:15:13PM +0000, Hugh Dickins wrote:
> > I've only just found that we have to supply the __GFP_COMP flag to get
> > this working. And one of the routes through snd_dma_alloc_pages goes
> > to sbus_alloc_consistent. Would you be happy for me to send Andrew a
> > patch with sparc and sparc64 sbus_alloc_consistent including __GFP_COMP?
> > Ought I to do the same in the sparc and sparc64 pci_alloc_consistent??
>
> I usually end up deferring to Dave on the driver issues, but this time
> I can independently agree in an informed manner.

What is it needed for in this case? We never try to use those
pci_alloc_consistent() pages independantly, ie. freeing up
individual pages from a non-zero order allocation.

Just curious. :-)