b58e90be71
[ Upstream commit 30de2b541af98179780054836b48825fcfba4408 ] During event processing, events are read from the event queue one by one until the queue is empty.If the master device continuously requests address access at the same time and the SMMU generates events, the cyclic processing of the event takes a long time and softlockup warnings may be reported. arm-smmu-v3 arm-smmu-v3.34.auto: event 0x0a received: arm-smmu-v3 arm-smmu-v3.34.auto: 0x00007f220000280a arm-smmu-v3 arm-smmu-v3.34.auto: 0x000010000000007e arm-smmu-v3 arm-smmu-v3.34.auto: 0x00000000034e8670 watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [irq/268-arm-smm:247] Call trace: _dev_info+0x7c/0xa0 arm_smmu_evtq_thread+0x1c0/0x230 irq_thread_fn+0x30/0x80 irq_thread+0x128/0x210 kthread+0x134/0x138 ret_from_fork+0x10/0x1c Kernel panic - not syncing: softlockup: hung tasks Fix this by calling cond_resched() after the event information is printed. Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com> Link: https://lore.kernel.org/r/20220119070754.26528-1-zhouguanghui1@huawei.com Signed-off-by: Will Deacon <will@kernel.org> 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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.