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    SubjectRe: fuse, get_user_pages, flush_anon_page, aliasing caches and all that again
    On Sun, Dec 31, 2006 at 01:47:56AM -0800, David Miller wrote:
    > From: Arjan van de Ven <arjan@infradead.org>
    > Date: Sun, 31 Dec 2006 10:27:22 +0100
    > > > However, it's not only FUSE which is suffering - direct-IO also doesn't
    > > > work.
    > >
    > > for direct-IO the kernel won't touch the data *at all*... (that's the
    > > point ;)
    > >
    > > is it still an issue then?
    >
    > It can be an issue with virtual caches if the "I/O" is done
    > using cpu loads and stores, but we should be handling that
    > with explicit flushing anyways.
    >
    > The core of the problem is that ARM doesn't look for the user
    > mappings for anonymous pages when flush_dcache_page() is invoked.
    > I think as a temporary fix it could walk the RMAP list and
    > use that to find the user virtual mappings. Would that work
    > Russel?

    I'm willing to do that - and I guess this means we can probably do this
    instead of walking the list of VMAs for the shared mapping, thereby
    hitting both anonymous and shared mappings with the same code?

    --
    Russell King
    Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    maintainer of:
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