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authorPaul E. McKenney <paulmck@kernel.org>2021-03-04 14:46:59 -0800
committerPaul E. McKenney <paulmck@kernel.org>2021-05-10 16:04:24 -0700
commit9fc98e3143de7b7e8d766aef41b46ec0bc0ae4ca (patch)
tree0a02c503c171aa6b00d890d8c232153d03b6914b /kernel
parent06a3ec9205d570526665c2071d1a5492c3091a54 (diff)
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rcu-tasks: Add block comment laying out RCU Rude design
This commit adds a block comment that gives a high-level overview of how RCU Rude grace periods progress. It also gives an overview of the memory ordering. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcu/tasks.h9
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 94d2c2c7f0ab..d6aa352cd705 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -645,8 +645,13 @@ void exit_tasks_rcu_finish(void) { exit_tasks_rcu_finish_trace(current); }
// passing an empty function to schedule_on_each_cpu(). This approach
// provides an asynchronous call_rcu_tasks_rude() API and batching
// of concurrent calls to the synchronous synchronize_rcu_rude() API.
-// This sends IPIs far and wide and induces otherwise unnecessary context
-// switches on all online CPUs, whether idle or not.
+// This invokes schedule_on_each_cpu() in order to send IPIs far and wide
+// and induces otherwise unnecessary context switches on all online CPUs,
+// whether idle or not.
+//
+// Callback handling is provided by the rcu_tasks_kthread() function.
+//
+// Ordering is provided by the scheduler's context-switch code.
// Empty function to allow workqueues to force a context switch.
static void rcu_tasks_be_rude(struct work_struct *work)