Re: get_user_pages ?

[Nick Piggin <nickpiggin@yahoo.com.au>]

Mark Hounschell wrote:
> For some reason (unknown to me) the VM_IO and even newer VM_PFNMAP
> vm_flags are set when I use this call causing it to fail for me. I'm
> currently using 2.6.16.9 on an x86 platform.

[...]

> I'm not the author of any of this code so please gentle with me. Nor do
> I have much of an understanding of the vm system. Any help in how this
> task should really be accomplished, taken the stated limitations of the
> pci card in mind, would be greatly appreciated. And any help as to what
> would just make it work again would also be greatly appreciated. As I
> stated above this all worked fine until the VM_PFNMAP bit was added to
> the vm->flags and subsequently checked for in the get_user_pages call.

remap_pfn_range isn't the best API for someone who needs get_user_pages.
remap_pfn_range operates on the pfn level only, so underlying addresses
may not even have a struct page.

This area is going through some changes lately. If you want something to
quickly get things working, removing VM_PFNMAP from your vma flags should
work.

-- 
SUSE Labs, Novell Inc.
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