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    SubjectRe: Sleeping in RCU list traversal
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    Hello.

    Thank you for pointing out.

    Jun WANG wrote:
    > >rcu_read_lock();
    > >list_for_each_rcu(p, ...) {
    > > ptr = list_entry(p, struct ..., list);
    > > /* Grab a reference to "ptr". */
    > > rcu_read_unlock();
    > > my_task_that_may_sleep(ptr);
    > > rcu_read_lock();
    > > /* Drop a reference to "ptr". */
    > > }
    > > rcu_read_unlock();
    >
    > In Document/RCU/whatisRCU.txt
    > Note that the value returned by rcu_dereference() is valid
    > only within the enclosing RCU read-side critical section.
    Excuse me, but I think "p" is used only between rcu_read_lock() and rcu_read_unlock().
    Is it illegal to use "ptr" after rcu_read_unlock() if "ptr" is obtained before rcu_read_unlock() ?

    Regards.

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