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    SubjectRe: [PATCH v6 18/24] mm: Try spin lock in speculative path
    On Fri, Jan 12, 2018 at 06:26:02PM +0100, Laurent Dufour wrote:
    > There is a deadlock when a CPU is doing a speculative page fault and
    > another one is calling do_unmap().
    >
    > The deadlock occurred because the speculative path try to spinlock the
    > pte while the interrupt are disabled. When the other CPU in the
    > unmap's path has locked the pte then is waiting for all the CPU to
    > invalidate the TLB. As the CPU doing the speculative fault have the
    > interrupt disable it can't invalidate the TLB, and can't get the lock.
    >
    > Since we are in a speculative path, we can race with other mm action.
    > So let assume that the lock may not get acquired and fail the
    > speculative page fault.

    It seems like you introduced this bug in the previous patch, and now
    you're fixing it in this patch? Why not merge the two?

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