Re: VM_RESERVED [was Re: mapping user space buffer to kernel address space]

[Jeff Garzik]

Andrea Arcangeli wrote:
> On Fri, Oct 20, 2000 at 01:46:53PM -0400, Jeff Garzik wrote:
> > In any case, we shouldn't modify videodev.c to call vma_reserve()...
> > Let the driver's mmap operation do that or not do that, as it chooses.
> 
> It can't with the current mmap video4linux kernel API.

Why?  I don't see anything special that video_mmap() does, and IMHO the
driver needs to have control over that sort of thing.  video4linux mmap
area could be vmalloc'd memory, kmalloc'd memory, get_free_pages memory,
reserve_bootmem memory, or PCI shared memory...  Hell in theory it could
be a dummy framegrabber driver with mmap'able memory that can be swapped
out.


> In practice it doesn't matter because none driver (before your VIA soundcard :)
> is implementing the swapout callback. And vma_reserve fits perfectly in your
> ->nopage driver too.

If I understand your patch, I should call vma_reserve(), and then
completely remove my no-op swapout().  Correct?

        Jeff


-- 
Jeff Garzik                    | The difference between laziness and
Building 1024                  | prioritization is the end result.
MandrakeSoft                   |
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