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    SubjectRe: INFO: possible circular locking dependency detected
    egad! Looking at this code more, there's nothing keeping
    t->rcu_read_unlock_special safe! If it can be modified by the kthread,
    and current, then we must use atomic operations or modify under lock.
    Otherwise the old read/modify/write can corrupt it.

    t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_BLOCKED;

    is done before the lock is taken in rcu_read_unlock_special. If the
    kthread is running rcu_boost() then its code:

    t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BOOSTED;

    Can even negate the removing of the RCU_READ_UNLOCK_BLOCKED!

    -- Steve

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      Last update: 2011-07-14 19:49    [W:0.019 / U:249.124 seconds]
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