diff options
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 853c7b8ea833..32664347091a 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -70,11 +70,11 @@ static void __init rcu_bootup_announce_oddness(void) { if (IS_ENABLED(CONFIG_RCU_TRACE)) pr_info("\tRCU debugfs-based tracing is enabled.\n"); - if ((IS_ENABLED(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 64) || - (!IS_ENABLED(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 32)) + if ((IS_ENABLED(CONFIG_64BIT) && RCU_FANOUT != 64) || + (!IS_ENABLED(CONFIG_64BIT) && RCU_FANOUT != 32)) pr_info("\tCONFIG_RCU_FANOUT set to non-default value of %d\n", - CONFIG_RCU_FANOUT); - if (IS_ENABLED(CONFIG_RCU_FANOUT_EXACT)) + RCU_FANOUT); + if (rcu_fanout_exact) pr_info("\tHierarchical RCU autobalancing is disabled.\n"); if (IS_ENABLED(CONFIG_RCU_FAST_NO_HZ)) pr_info("\tRCU dyntick-idle grace-period acceleration is enabled.\n"); @@ -86,10 +86,10 @@ static void __init rcu_bootup_announce_oddness(void) pr_info("\tAdditional per-CPU info printed with stalls.\n"); if (NUM_RCU_LVL_4 != 0) pr_info("\tFour-level hierarchy is enabled.\n"); - if (CONFIG_RCU_FANOUT_LEAF != 16) + if (RCU_FANOUT_LEAF != 16) pr_info("\tBuild-time adjustment of leaf fanout to %d.\n", - CONFIG_RCU_FANOUT_LEAF); - if (rcu_fanout_leaf != CONFIG_RCU_FANOUT_LEAF) + RCU_FANOUT_LEAF); + if (rcu_fanout_leaf != RCU_FANOUT_LEAF) pr_info("\tBoot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf); if (nr_cpu_ids != NR_CPUS) pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids); @@ -315,9 +315,11 @@ void rcu_read_unlock_special(struct task_struct *t) t->rcu_read_unlock_special.b.blocked = false; /* - * Remove this task from the list it blocked on. The - * task can migrate while we acquire the lock, but at - * most one time. So at most two passes through loop. + * Remove this task from the list it blocked on. The task + * now remains queued on the rcu_node corresponding to + * the CPU it first blocked on, so the first attempt to + * acquire the task's rcu_node's ->lock will succeed. + * Keep the loop and add a WARN_ON() out of sheer paranoia. */ for (;;) { rnp = t->rcu_blocked_node; @@ -325,6 +327,7 @@ void rcu_read_unlock_special(struct task_struct *t) smp_mb__after_unlock_lock(); if (rnp == t->rcu_blocked_node) break; + WARN_ON_ONCE(1); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } empty_norm = !rcu_preempt_blocked_readers_cgp(rnp); |
