Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 17/17] rcu: Add check for CPUs going offline with callbacks queued | Date | Fri, 22 Jun 2012 08:35:12 -0700 |
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From: "Paul E. McKenney" <paul.mckenney@linaro.org>
If a CPU goes offline with callbacks queued, those callbacks might be indefinitely postponed, which can result in a system hang. This commit therefore inserts warnings for this condition.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> --- kernel/rcutree.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index c0cc41f..f849202 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1506,6 +1506,9 @@ static void rcu_cleanup_dead_cpu(int cpu, struct rcu_state *rsp) raw_spin_unlock_irqrestore(&rnp->lock, flags); if (need_report & RCU_OFL_TASKS_EXP_GP) rcu_report_exp_rnp(rsp, rnp, true); + WARN_ONCE(rdp->qlen != 0 || rdp->nxtlist != NULL, + "rcu_cleanup_dead_cpu: Callbacks on offline CPU %d: qlen=%lu, nxtlist=%p\n", + cpu, rdp->qlen, rdp->nxtlist); } #else /* #ifdef CONFIG_HOTPLUG_CPU */ -- 1.7.8
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