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SubjectRe: [PATCH tip/core/rcu 19/23] rcu: Adjust for unconditional ->completed assignment
On Thu, Aug 30, 2012 at 11:18:34AM -0700, Paul E. McKenney wrote:
> From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
>
> Now that the rcu_node structures' ->completed fields are unconditionally
> assigned at grace-period cleanup time, they should already have the
> correct value for the new grace period at grace-period initialization
> time. This commit therefore inserts a WARN_ON_ONCE() to verify this
> invariant.
>
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Reviewed-by: Josh Triplett <josh@joshtriplett.org>

> kernel/rcutree.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/kernel/rcutree.c b/kernel/rcutree.c
> index 1373388..86903df 100644
> --- a/kernel/rcutree.c
> +++ b/kernel/rcutree.c
> @@ -1098,6 +1098,7 @@ static int rcu_gp_init(struct rcu_state *rsp)
> rcu_preempt_check_blocked_tasks(rnp);
> rnp->qsmask = rnp->qsmaskinit;
> rnp->gpnum = rsp->gpnum;
> + WARN_ON_ONCE(rnp->completed != rsp->completed);
> rnp->completed = rsp->completed;
> if (rnp == rdp->mynode)
> rcu_start_gp_per_cpu(rsp, rnp, rdp);
> @@ -2795,7 +2796,8 @@ static void __init rcu_init_one(struct rcu_state *rsp,
> raw_spin_lock_init(&rnp->fqslock);
> lockdep_set_class_and_name(&rnp->fqslock,
> &rcu_fqs_class[i], fqs[i]);
> - rnp->gpnum = 0;
> + rnp->gpnum = rsp->gpnum;
> + rnp->completed = rsp->completed;
> rnp->qsmask = 0;
> rnp->qsmaskinit = 0;
> rnp->grplo = j * cpustride;
> --
> 1.7.8
>


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