Commit-ID: a8f4cbadfb5c5f7f5d9eef70821276a4e2e9289d Gitweb: http://git.kernel.org/tip/a8f4cbadfb5c5f7f5d9eef70821276a4e2e9289d Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> AuthorDate: Fri, 31 Oct 2014 13:48:41 -0700 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Tue, 6 Jan 2015 11:02:45 -0800 rcu: Shorten irq-disable region in rcu_cleanup_dead_cpu() Now that we are not migrating callbacks, there is no need to hold the ->orphan_lock across the the ->qsmaskinit bit-clearing process. This commit therefore releases ->orphan_lock immediately after adopting the orphaned RCU callbacks. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> --- kernel/rcu/tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 84f16cf..990b406 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2289,14 +2289,14 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) /* Orphan the dead CPU's callbacks, and adopt them if appropriate. */ rcu_send_cbs_to_orphanage(cpu, rsp, rnp, rdp); rcu_adopt_orphan_cbs(rsp, flags); + raw_spin_unlock_irqrestore(&rsp->orphan_lock, flags); /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ - raw_spin_lock(&rnp->lock); /* irqs already disabled. */ + raw_spin_lock_irqsave(&rnp->lock, flags); smp_mb__after_unlock_lock(); /* Enforce GP memory-order guarantee. */ rnp->qsmaskinit &= ~rdp->grpmask; if (rnp->qsmaskinit == 0 && !rcu_preempt_has_tasks(rnp)) rcu_cleanup_dead_rnp(rnp); - raw_spin_unlock(&rsp->orphan_lock); /* irqs remain disabled. */ raw_spin_unlock_irqrestore(&rnp->lock, flags); WARN_ONCE(rdp->qlen != 0 || rdp->nxtlist != NULL, "rcu_cleanup_dead_cpu: Callbacks on offline CPU %d: qlen=%lu, nxtlist=%p\n", -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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