diff options
| -rw-r--r-- | kernel/rcu/tree.c | 3 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 57 |
2 files changed, 22 insertions, 38 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 03503e295b51..ee77858403f8 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4086,8 +4086,7 @@ int rcutree_prepare_cpu(unsigned int cpu) raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */ /* * Lock in case the CB/GP kthreads are still around handling - * old callbacks (longer term we should flush all callbacks - * before completing CPU offline) + * old callbacks. */ rcu_nocb_lock(rdp); if (rcu_segcblist_empty(&rdp->cblist)) /* No early-boot CBs? */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 013142d1ef76..9fd8588bba14 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2399,23 +2399,18 @@ static int rdp_offload_toggle(struct rcu_data *rdp, return 0; } -static int __rcu_nocb_rdp_deoffload(struct rcu_data *rdp) +static long rcu_nocb_rdp_deoffload(void *arg) { + struct rcu_data *rdp = arg; struct rcu_segcblist *cblist = &rdp->cblist; unsigned long flags; int ret; + WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); + pr_info("De-offloading %d\n", rdp->cpu); rcu_nocb_lock_irqsave(rdp, flags); - /* - * If there are still pending work offloaded, the offline - * CPU won't help much handling them. - */ - if (cpu_is_offline(rdp->cpu) && !rcu_segcblist_empty(&rdp->cblist)) { - rcu_nocb_unlock_irqrestore(rdp, flags); - return -EBUSY; - } ret = rdp_offload_toggle(rdp, false, flags); swait_event_exclusive(rdp->nocb_state_wq, @@ -2446,14 +2441,6 @@ static int __rcu_nocb_rdp_deoffload(struct rcu_data *rdp) return ret; } -static long rcu_nocb_rdp_deoffload(void *arg) -{ - struct rcu_data *rdp = arg; - - WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); - return __rcu_nocb_rdp_deoffload(rdp); -} - int rcu_nocb_cpu_deoffload(int cpu) { struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); @@ -2466,12 +2453,14 @@ int rcu_nocb_cpu_deoffload(int cpu) mutex_lock(&rcu_state.barrier_mutex); cpus_read_lock(); if (rcu_rdp_is_offloaded(rdp)) { - if (cpu_online(cpu)) + if (cpu_online(cpu)) { ret = work_on_cpu(cpu, rcu_nocb_rdp_deoffload, rdp); - else - ret = __rcu_nocb_rdp_deoffload(rdp); - if (!ret) - cpumask_clear_cpu(cpu, rcu_nocb_mask); + if (!ret) + cpumask_clear_cpu(cpu, rcu_nocb_mask); + } else { + pr_info("NOCB: Can't CB-deoffload an offline CPU\n"); + ret = -EINVAL; + } } cpus_read_unlock(); mutex_unlock(&rcu_state.barrier_mutex); @@ -2480,12 +2469,14 @@ int rcu_nocb_cpu_deoffload(int cpu) } EXPORT_SYMBOL_GPL(rcu_nocb_cpu_deoffload); -static int __rcu_nocb_rdp_offload(struct rcu_data *rdp) +static long rcu_nocb_rdp_offload(void *arg) { + struct rcu_data *rdp = arg; struct rcu_segcblist *cblist = &rdp->cblist; unsigned long flags; int ret; + WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); /* * For now we only support re-offload, ie: the rdp must have been * offloaded on boot first. @@ -2525,14 +2516,6 @@ static int __rcu_nocb_rdp_offload(struct rcu_data *rdp) return ret; } -static long rcu_nocb_rdp_offload(void *arg) -{ - struct rcu_data *rdp = arg; - - WARN_ON_ONCE(rdp->cpu != raw_smp_processor_id()); - return __rcu_nocb_rdp_offload(rdp); -} - int rcu_nocb_cpu_offload(int cpu) { struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); @@ -2541,12 +2524,14 @@ int rcu_nocb_cpu_offload(int cpu) mutex_lock(&rcu_state.barrier_mutex); cpus_read_lock(); if (!rcu_rdp_is_offloaded(rdp)) { - if (cpu_online(cpu)) + if (cpu_online(cpu)) { ret = work_on_cpu(cpu, rcu_nocb_rdp_offload, rdp); - else - ret = __rcu_nocb_rdp_offload(rdp); - if (!ret) - cpumask_set_cpu(cpu, rcu_nocb_mask); + if (!ret) + cpumask_set_cpu(cpu, rcu_nocb_mask); + } else { + pr_info("NOCB: Can't CB-offload an offline CPU\n"); + ret = -EINVAL; + } } cpus_read_unlock(); mutex_unlock(&rcu_state.barrier_mutex); |