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| author | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2020-12-09 21:27:31 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-12-15 00:31:13 +0100 |
| commit | 1b04fa9900263b4e217ca2509fd778b32c2b4eb2 (patch) | |
| tree | 9d5e4a413b1e641955514dc16b4b2ba4a7924c5e /kernel | |
| parent | Linux 5.10-rc7 (diff) | |
| download | linux-1b04fa9900263b4e217ca2509fd778b32c2b4eb2.tar.xz linux-1b04fa9900263b4e217ca2509fd778b32c2b4eb2.zip | |
rcu-tasks: Move RCU-tasks initialization to before early_initcall()
PowerPC testing encountered boot failures due to RCU Tasks not being
fully initialized until core_initcall() time. This commit therefore
initializes RCU Tasks (along with Rude RCU and RCU Tasks Trace) just
before early_initcall() time, thus allowing waiting on RCU Tasks grace
periods from early_initcall() handlers.
Link: https://lore.kernel.org/rcu/87eekfh80a.fsf@dja-thinkpad.axtens.net/
Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall")
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tasks.h | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index d5d9f2d03e8a..73bbe792fe1e 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -241,7 +241,7 @@ static int __noreturn rcu_tasks_kthread(void *arg) } } -/* Spawn RCU-tasks grace-period kthread, e.g., at core_initcall() time. */ +/* Spawn RCU-tasks grace-period kthread. */ static void __init rcu_spawn_tasks_kthread_generic(struct rcu_tasks *rtp) { struct task_struct *t; @@ -569,7 +569,6 @@ static int __init rcu_spawn_tasks_kthread(void) rcu_spawn_tasks_kthread_generic(&rcu_tasks); return 0; } -core_initcall(rcu_spawn_tasks_kthread); #ifndef CONFIG_TINY_RCU static void show_rcu_tasks_classic_gp_kthread(void) @@ -697,7 +696,6 @@ static int __init rcu_spawn_tasks_rude_kthread(void) rcu_spawn_tasks_kthread_generic(&rcu_tasks_rude); return 0; } -core_initcall(rcu_spawn_tasks_rude_kthread); #ifndef CONFIG_TINY_RCU static void show_rcu_tasks_rude_gp_kthread(void) @@ -975,6 +973,11 @@ static void rcu_tasks_trace_pregp_step(void) static void rcu_tasks_trace_pertask(struct task_struct *t, struct list_head *hop) { + // During early boot when there is only the one boot CPU, there + // is no idle task for the other CPUs. Just return. + if (unlikely(t == NULL)) + return; + WRITE_ONCE(t->trc_reader_special.b.need_qs, false); WRITE_ONCE(t->trc_reader_checked, false); t->trc_ipi_to_cpu = -1; @@ -1200,7 +1203,6 @@ static int __init rcu_spawn_tasks_trace_kthread(void) rcu_spawn_tasks_kthread_generic(&rcu_tasks_trace); return 0; } -core_initcall(rcu_spawn_tasks_trace_kthread); #ifndef CONFIG_TINY_RCU static void show_rcu_tasks_trace_gp_kthread(void) @@ -1229,6 +1231,21 @@ void show_rcu_tasks_gp_kthreads(void) } #endif /* #ifndef CONFIG_TINY_RCU */ +void __init rcu_init_tasks_generic(void) +{ +#ifdef CONFIG_TASKS_RCU + rcu_spawn_tasks_kthread(); +#endif + +#ifdef CONFIG_TASKS_RUDE_RCU + rcu_spawn_tasks_rude_kthread(); +#endif + +#ifdef CONFIG_TASKS_TRACE_RCU + rcu_spawn_tasks_trace_kthread(); +#endif +} + #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ static inline void rcu_tasks_bootup_oddness(void) {} void show_rcu_tasks_gp_kthreads(void) {} |