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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-10-31 13:48:41 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-01-06 11:02:45 -0800
commita8f4cbadfb5c5f7f5d9eef70821276a4e2e9289d (patch)
tree78725990111ebe677c9b6df8101f80a202011cdd /kernel/rcu
parentrcu: Don't migrate blocked tasks even if all corresponding CPUs offline (diff)
downloadlinux-dev-a8f4cbadfb5c5f7f5d9eef70821276a4e2e9289d.tar.xz
linux-dev-a8f4cbadfb5c5f7f5d9eef70821276a4e2e9289d.zip
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@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 84f16cf05991..990b406faf4e 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",