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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-12-16 15:55:48 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 16:31:45 +0100 |
| commit | 83f20fa16909799082609830929ee3c067bcb098 (patch) | |
| tree | 149d2425176ab5c09f6d48206fcc28c0891f8030 /kernel | |
| parent | d481fd6064bf215d7c5068e15aa390c3b16c9cd0 (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 72770a551c24..fa6ae9ed2e1d 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -577,7 +577,9 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp) mask = leaf_node_cpu_bit(rnp, cpu); if (!(rnp->expmask & mask)) continue; + preempt_disable(); // For smp_processor_id() in dump_cpu_task(). dump_cpu_task(cpu); + preempt_enable(); } } jiffies_stall = 3 * rcu_jiffies_till_stall_check() + 3; |