• Longfang Liu's avatar
    crypto: hisilicon/qm - prevent soft lockup in receive loop · 33fc506d
    Longfang Liu authored
    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: default avatarLongfang Liu <liulongfang@huawei.com>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    33fc506d
qm.c 131 KB