diff options
| author | Paul E. McKenney | 2022-12-16 15:55:48 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-03-10 09:33:48 +0100 |
| commit | 05737bd85c1098befde8d340dbd78fe28da1b9ee (patch) | |
| tree | 2c0c63f1ac94c9af6209b0c1d2717c7d5d124314 /kernel | |
| parent | 4a501b4ef88170a860be55ad98efb4aab9e1bdfe (diff) | |
rcu: Suppress smp_processor_id() complaint in synchronize_rcu_expedited_wait()
[ Upstream commit 2d7f00b2f01301d6e41fd4a28030dab0442265be ]
The normal grace period's RCU CPU stall warnings are invoked from the
scheduling-clock interrupt handler, and can thus invoke smp_processor_id()
with impunity, which allows them to directly invoke dump_cpu_task().
In contrast, the expedited grace period's RCU CPU stall warnings are
invoked from process context, which causes the dump_cpu_task() function's
calls to smp_processor_id() to complain bitterly in debug kernels.
This commit therefore causes synchronize_rcu_expedited_wait() to disable
preemption around its call to dump_cpu_task().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree_exp.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 18e9b4cd78ef..60732264a7d0 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -667,7 +667,9 @@ static void synchronize_rcu_expedited_wait(void) mask = leaf_node_cpu_bit(rnp, cpu); if (!(READ_ONCE(rnp->expmask) & mask)) continue; + preempt_disable(); // For smp_processor_id() in dump_cpu_task(). dump_cpu_task(cpu); + preempt_enable(); } } jiffies_stall = 3 * rcu_exp_jiffies_till_stall_check() + 3; |