We hit the following BUG:
BUG: scheduling while atomic: kworker/1:1/24117/0x00000002
Preemption disabled at:
[<ffffffffb61fd824>] padata_do_serial+0x24/0x110
CPU: 1 PID: 24117 Comm: kworker/1:1 Not tainted 4.18.0-56.rt9.107.el8.x86_64
#1
Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30
11/14/2017
Workqueue: pencrypt padata_parallel_worker
Call Trace:
dump_stack+0x5c/0x80
? padata_do_serial+0x24/0x110
__schedule_bug.cold.83+0x8e/0x9b
__schedule+0x5a0/0x680
schedule+0x39/0xd0
rt_spin_lock_slowlock_locked+0x10e/0x2b0
rt_spin_lock_slowlock+0x50/0x80
padata_do_serial+0x4d/0x110
padata_parallel_worker+0xaf/0xe0
process_one_work+0x183/0x3b0
? process_one_work+0x3b0/0x3b0
worker_thread+0x30/0x3d0
? process_one_work+0x3b0/0x3b0
kthread+0x112/0x130
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x35/0x40
and the cause is a spin_lock() taken inside a get_cpu() section.
Convert the get/put_cpu to get/put_cpu_light to fix the BUG while reducing the
preempt_disable section.
Signed-off-by: Daniel Bristot de Oliveira <bris...@redhat.com>
Reviewed-by: Clark Williams <willi...@redhat.com>
Cc: Sebastian Andrzej Siewior <bige...@linutronix.de>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Clark Williams <willi...@redhat.com>
Cc: linux-rt-us...@vger.kernel.org
Cc: linux-cry...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
diff --git a/kernel/padata.c b/kernel/padata.c
index d568cc56405f..bfcbdeb20ba5 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -295,7 +295,7 @@ static void padata_reorder_timer(struct timer_list *t)
unsigned int weight;
int target_cpu, cpu;
- cpu = get_cpu();
+ cpu = get_cpu_light();
/* We don't lock pd here to not interfere with parallel processing
* padata_reorder() calls on other CPUs. We just need any CPU out of
@@ -321,7 +321,7 @@ static void padata_reorder_timer(struct timer_list *t)
padata_reorder(pd);
}
- put_cpu();
+ put_cpu_light();
}
static void padata_serial_worker(struct work_struct *serial_work)
@@ -369,7 +369,7 @@ void padata_do_serial(struct padata_priv *padata)
pd = padata->pd;
- cpu = get_cpu();
+ cpu = get_cpu_light();
/* We need to run on the same CPU padata_do_parallel(.., padata, ..)
* was called on -- or, at least, enqueue the padata object into the
@@ -387,7 +387,7 @@ void padata_do_serial(struct padata_priv *padata)
list_add_tail(&padata->list, &pqueue->reorder.list);
spin_unlock(&pqueue->reorder.lock);
- put_cpu();
+ put_cpu_light();
/* If we're running on the wrong CPU, call padata_reorder() via a
* kernel worker.
--
2.17.2
