c7f514e266
[ Upstream commit 33fc506d2ac514be1072499a263c3bff8c7c95a0 ] 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 <liulongfang@huawei.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.