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| author | Paul E. McKenney <paulmck@kernel.org> | 2021-03-31 10:59:05 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-05-10 16:22:54 -0700 |
| commit | 8e4b1d2bc198e34b48fc7cc3a3c5a2fcb269e271 (patch) | |
| tree | 11f15f922cc31b1a9bab24e370735fe9e38f63aa /kernel/rcu | |
| parent | 277ffe1b709280856391663c2ca5685a28308fc5 (diff) | |
| download | lwn-8e4b1d2bc198e34b48fc7cc3a3c5a2fcb269e271.tar.gz lwn-8e4b1d2bc198e34b48fc7cc3a3c5a2fcb269e271.zip | |
rcu: Invoke rcu_spawn_core_kthreads() from rcu_spawn_gp_kthread()
Currently, rcu_spawn_core_kthreads() is invoked via an early_initcall(),
which works, except that rcu_spawn_gp_kthread() is also invoked via an
early_initcall() and rcu_spawn_core_kthreads() relies on adjustments to
kthread_prio that are carried out by rcu_spawn_gp_kthread(). There is
no guaranttee of ordering among early_initcall() handlers, and thus no
guarantee that kthread_prio will be properly checked and range-limited
at the time that rcu_spawn_core_kthreads() needs it.
In most cases, this bug is harmless. After all, the only reason that
rcu_spawn_gp_kthread() adjusts the value of kthread_prio is if the user
specified a nonsensical value for this boot parameter, which experience
indicates is rare.
Nevertheless, a bug is a bug. This commit therefore causes the
rcu_spawn_core_kthreads() function to be invoked directly from
rcu_spawn_gp_kthread() after any needed adjustments to kthread_prio have
been carried out.
Fixes: 48d07c04b4cc ("rcu: Enable elimination of Tree-RCU softirq processing")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 06f3de96997c..2532e584e95f 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2889,7 +2889,6 @@ static int __init rcu_spawn_core_kthreads(void) "%s: Could not start rcuc kthread, OOM is now expected behavior\n", __func__); return 0; } -early_initcall(rcu_spawn_core_kthreads); /* * Handle any core-RCU processing required by a call_rcu() invocation. @@ -4450,6 +4449,7 @@ static int __init rcu_spawn_gp_kthread(void) wake_up_process(t); rcu_spawn_nocb_kthreads(); rcu_spawn_boost_kthreads(); + rcu_spawn_core_kthreads(); return 0; } early_initcall(rcu_spawn_gp_kthread); |