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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-11-03 18:15:17 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-01-06 11:02:47 -0800 |
| commit | 3e9f5c70d85060ff0db71826e2048daffec336e7 (patch) | |
| tree | db84eacf19f182ce185afa165fe2b1aa1a8569b1 /kernel/rcu/tree_plugin.h | |
| parent | 96e92021d4fad8543d598b5e4926cb34fd40c4c4 (diff) | |
| download | lwn-3e9f5c70d85060ff0db71826e2048daffec336e7.tar.gz lwn-3e9f5c70d85060ff0db71826e2048daffec336e7.zip | |
rcu: Don't spawn rcub kthreads on root rcu_node structure
Now that offlining CPUs no longer moves leaf rcu_node structures'
->blkd_tasks lists to the root, there is no way for the root rcu_node
structure's ->blkd_task list to be nonempty, unless the root node is also
the sole leaf node. This commit therefore refrains from creating an rcub
kthread for the root rcu_node structure unless it is also the sole leaf.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index bcc6d9134d47..3e64bb197b1a 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1352,12 +1352,8 @@ static void __init rcu_spawn_boost_kthreads(void) for_each_possible_cpu(cpu) per_cpu(rcu_cpu_has_work, cpu) = 0; BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec)); - rnp = rcu_get_root(rcu_state_p); - (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp); - if (NUM_RCU_NODES > 1) { - rcu_for_each_leaf_node(rcu_state_p, rnp) - (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp); - } + rcu_for_each_leaf_node(rcu_state_p, rnp) + (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp); } static void rcu_prepare_kthreads(int cpu) |