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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-12-17 02:55:48 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2023-01-04 04:28:34 +0300 |
| commit | 2d7f00b2f01301d6e41fd4a28030dab0442265be (patch) | |
| tree | 1c9f27780bb72d4786b9c2901c2dc1890293e5be /kernel/rcu | |
| parent | 0cae5ded535c3a80aed94f119bbd4ee3ae284a65 (diff) | |
| download | linux-2d7f00b2f01301d6e41fd4a28030dab0442265be.tar.xz | |
rcu: Suppress smp_processor_id() complaint in synchronize_rcu_expedited_wait()
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>
Diffstat (limited to 'kernel/rcu')
| -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 ed6c3cce28f2..927abaf6c822 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; |