diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2019-07-10 08:01:01 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2019-10-05 10:46:05 -0700 |
| commit | 366237e7b0833faa2d8da7a8d7d7da8c3ca802e5 (patch) | |
| tree | 5944c55f1dd161c7c1a2420fb259854930324df2 | |
| parent | d38e6dc6ed0dfef8d323354031a1ee1a7cfdedc1 (diff) | |
stop_machine: Provide RCU quiescent state in multi_cpu_stop()
When multi_cpu_stop() loops waiting for other tasks, it can trigger an RCU
CPU stall warning. This can be misleading because what is instead needed
is information on whatever task is blocking multi_cpu_stop(). This commit
therefore inserts an RCU quiescent state into the multi_cpu_stop()
function's waitloop.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | include/linux/rcutree.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 2 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 1 |
3 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 18b1ed9864b0..c5147de885ec 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -37,6 +37,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func); void rcu_barrier(void); bool rcu_eqs_special_set(int cpu); +void rcu_momentary_dyntick_idle(void); unsigned long get_state_synchronize_rcu(void); void cond_synchronize_rcu(unsigned long oldstate); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 238f93b4b0a4..a5c296d202ae 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -364,7 +364,7 @@ bool rcu_eqs_special_set(int cpu) * * The caller must have disabled interrupts and must not be idle. */ -static void __maybe_unused rcu_momentary_dyntick_idle(void) +void rcu_momentary_dyntick_idle(void) { int special; diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index c7031a22aa7b..34c4f117d8c7 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -233,6 +233,7 @@ static int multi_cpu_stop(void *data) */ touch_nmi_watchdog(); } + rcu_momentary_dyntick_idle(); } while (curstate != MULTI_STOP_EXIT); local_irq_restore(flags); |