[PATCH v3 tip/core/rcu 11/34] rcu-tasks: Use unique names for RCU-Tasks kthreads and messages

paulmck
2020-03-27T22:26:16Z

This commit causes the flavors of RCU Tasks to use different names
for their kthreads and in their console messages.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/rcu/tasks.h | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
index 7f9ed20..9ca83c6 100644
--- a/kernel/rcu/tasks.h
+++ b/kernel/rcu/tasks.h
@@ -22,6 +22,8 @@ typedef void (*rcu_tasks_gp_func_t)(struct rcu_tasks *rtp);
* @kthread_ptr: This flavor's grace-period/callback-invocation kthread.
* @gp_func: This flavor's grace-period-wait function.
* @call_func: This flavor's call_rcu()-equivalent function.
+ * @name: This flavor's textual name.
+ * @kname: This flavor's kthread name.
*/
struct rcu_tasks {
struct rcu_head *cbs_head;
@@ -31,16 +33,20 @@ struct rcu_tasks {
struct task_struct *kthread_ptr;
rcu_tasks_gp_func_t gp_func;
call_rcu_func_t call_func;
+ char *name;
+ char *kname;
};

-#define DEFINE_RCU_TASKS(name, gp, call) \
-static struct rcu_tasks name = \
+#define DEFINE_RCU_TASKS(rt_name, gp, call, n) \
+static struct rcu_tasks rt_name = \
{ \
- .cbs_tail = &name.cbs_head, \
- .cbs_wq = __WAIT_QUEUE_HEAD_INITIALIZER(name.cbs_wq), \
- .cbs_lock = __RAW_SPIN_LOCK_UNLOCKED(name.cbs_lock), \
+ .cbs_tail = &rt_name.cbs_head, \
+ .cbs_wq = __WAIT_QUEUE_HEAD_INITIALIZER(rt_name.cbs_wq), \
+ .cbs_lock = __RAW_SPIN_LOCK_UNLOCKED(rt_name.cbs_lock), \
.gp_func = gp, \
.call_func = call, \
+ .name = n, \
+ .kname = #rt_name, \
}

/* Track exiting tasks in order to allow them to be waited for. */
@@ -145,8 +151,8 @@ static void __init rcu_spawn_tasks_kthread_generic(struct rcu_tasks *rtp)
{
struct task_struct *t;

- t = kthread_run(rcu_tasks_kthread, rtp, "rcu_tasks_kthread");
- if (WARN_ONCE(IS_ERR(t), "%s: Could not start Tasks-RCU grace-period kthread, OOM is now expected behavior\n", __func__))
+ t = kthread_run(rcu_tasks_kthread, rtp, "%s_kthread", rtp->kname);
+ if (WARN_ONCE(IS_ERR(t), "%s: Could not start %s grace-period kthread, OOM is now expected behavior\n", __func__, rtp->name))
return;
smp_mb(); /* Ensure others see full kthread. */
}
@@ -342,7 +348,7 @@ static void rcu_tasks_wait_gp(struct rcu_tasks *rtp)
}

void call_rcu_tasks(struct rcu_head *rhp, rcu_callback_t func);
-DEFINE_RCU_TASKS(rcu_tasks, rcu_tasks_wait_gp, call_rcu_tasks);
+DEFINE_RCU_TASKS(rcu_tasks, rcu_tasks_wait_gp, call_rcu_tasks, "RCU Tasks");

/**
* call_rcu_tasks() - Queue an RCU for invocation task-based grace period
@@ -437,7 +443,8 @@ static void rcu_tasks_rude_wait_gp(struct rcu_tasks *rtp)
}

void call_rcu_tasks_rude(struct rcu_head *rhp, rcu_callback_t func);
-DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude);
+DEFINE_RCU_TASKS(rcu_tasks_rude, rcu_tasks_rude_wait_gp, call_rcu_tasks_rude,
+ "RCU Tasks Rude");

/**
* call_rcu_tasks_rude() - Queue a callback rude task-based grace period
--
2.9.5