In the scenario where the accelerator business is fully loaded.
When the workqueue receiving messages and performing callback
processing, there are a large number of messages that need to be
received, and there are continuously messages that have been
processed and need to be received.
This will cause the receive loop here to be locked for a long time.
This scenario will cause watchdog timeout problems on OS with kernel
preemption turned off.
The error logs:
watchdog: BUG: soft lockup - CPU#23 stuck for 23s! [kworker/u262:1:1407]
[ 1461.978428][ C23] Call trace:
[ 1461.981890][ C23] complete+0x8c/0xf0
[ 1461.986031][ C23] kcryptd_async_done+0x154/0x1f4 [dm_crypt]
[ 1461.992154][ C23] sec_skcipher_callback+0x7c/0xf4 [hisi_sec2]
[ 1461.998446][ C23] sec_req_cb+0x104/0x1f4 [hisi_sec2]
[ 1462.003950][ C23] qm_poll_req_cb+0xcc/0x150 [hisi_qm]
[ 1462.009531][ C23] qm_work_process+0x60/0xc0 [hisi_qm]
[ 1462.015101][ C23] process_one_work+0x1c4/0x470
[ 1462.020052][ C23] worker_thread+0x150/0x3c4
[ 1462.024735][ C23] kthread+0x108/0x13c
[ 1462.028889][ C23] ret_from_fork+0x10/0x18
Therefore, it is necessary to add an actively scheduled operation in the
while loop to prevent this problem.
After adding it, no matter whether the OS turns on or off the kernel
preemption function. Neither will cause watchdog timeout issues.
Signed-off-by: Longfang Liu <[email protected]>
---
drivers/crypto/hisilicon/qm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
index 6ee24313d851..18599f3634c3 100644
--- a/drivers/crypto/hisilicon/qm.c
+++ b/drivers/crypto/hisilicon/qm.c
@@ -888,6 +888,8 @@ static void qm_poll_req_cb(struct hisi_qp *qp)
qm_db(qm, qp->qp_id, QM_DOORBELL_CMD_CQ,
qp->qp_status.cq_head, 0);
atomic_dec(&qp->qp_status.used);
+
+ cond_resched();
}
/* set c_flag */
--
2.24.0
On Fri, Oct 20, 2023 at 05:35:58PM +0800, Longfang Liu wrote:
> In the scenario where the accelerator business is fully loaded.
> When the workqueue receiving messages and performing callback
> processing, there are a large number of messages that need to be
> received, and there are continuously messages that have been
> processed and need to be received.
> This will cause the receive loop here to be locked for a long time.
> This scenario will cause watchdog timeout problems on OS with kernel
> preemption turned off.
>
> The error logs:
> watchdog: BUG: soft lockup - CPU#23 stuck for 23s! [kworker/u262:1:1407]
> [ 1461.978428][ C23] Call trace:
> [ 1461.981890][ C23] complete+0x8c/0xf0
> [ 1461.986031][ C23] kcryptd_async_done+0x154/0x1f4 [dm_crypt]
> [ 1461.992154][ C23] sec_skcipher_callback+0x7c/0xf4 [hisi_sec2]
> [ 1461.998446][ C23] sec_req_cb+0x104/0x1f4 [hisi_sec2]
> [ 1462.003950][ C23] qm_poll_req_cb+0xcc/0x150 [hisi_qm]
> [ 1462.009531][ C23] qm_work_process+0x60/0xc0 [hisi_qm]
> [ 1462.015101][ C23] process_one_work+0x1c4/0x470
> [ 1462.020052][ C23] worker_thread+0x150/0x3c4
> [ 1462.024735][ C23] kthread+0x108/0x13c
> [ 1462.028889][ C23] ret_from_fork+0x10/0x18
>
> Therefore, it is necessary to add an actively scheduled operation in the
> while loop to prevent this problem.
> After adding it, no matter whether the OS turns on or off the kernel
> preemption function. Neither will cause watchdog timeout issues.
>
> Signed-off-by: Longfang Liu <[email protected]>
> ---
> drivers/crypto/hisilicon/qm.c | 2 ++
> 1 file changed, 2 insertions(+)
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt