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    SubjectRe: [PATCH RFC tip/core/rcu 28/28] rcu: Fix idle-task checks
    On Wed, Nov 02, 2011 at 09:55:09PM -0700, Josh Triplett wrote:
    > On Wed, Nov 02, 2011 at 01:30:49PM -0700, Paul E. McKenney wrote:
    > > From: Paul E. McKenney <>
    > >
    > > RCU has traditionally relied on idle_cpu() to determine whether a given
    > > CPU is running in the context of an idle task, but recent changes have
    > > invalidated this approach. This commit therefore switches from idle_cpu
    > > to "current->pid != 0".
    > Could you elaborate a bit on "recent changes"? It looks like you mean
    > commit 908a3283728d92df36e0c7cd63304fd35e93a8a9; if so, could you add
    > that reference to the commit message?

    Will do!

    > Also, the hard-coded use of "current->pid != 0" concerns me. Could this
    > use some existing function? Does idle_task() help? If no appropriate
    > predicate exists, perhaps it should. is_idle_task(current)?

    I could use idle_task(), but that does quite a bit more work.
    The hard-coded "current->pid != 0" is used in a number of other places
    in the kernel, so there is precedent. Might be worth fixing globally
    as a separate fix, though.

    Thanx, Paul

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      Last update: 2011-11-03 22:03    [W:0.043 / U:10.100 seconds]
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