Messages in this thread | | | Date | Mon, 9 Sep 2002 12:13:48 +0100 | From | "Stephen C. Tweedie" <> | Subject | Re: [RFC] On paging of kernel VM. |
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Hi,
On Mon, Sep 09, 2002 at 10:20:53AM +0100, David Woodhouse wrote: > I think I'd like to introduce 'real' VMAs into kernel space, so that areas > in the vmalloc range can have 'real' vm_ops and more to the point a real > nopage function.
The alternative is a kmap-style mechanism for temporarily mapping pages beyond physical memory on demand. That would avoid the space limits we have on vmalloc etc; there's only a few tens of MB of address space we can use for mmap tricks in kernel space, so persistent maps are seriously constrained if you've got a lot of flash you want to map.
And with a kmap interface, your locking problems are much simpler --- you can trap accesses at source and you don't have to go hunting ptes to invalidate.
Cheers, Stephen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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