On 2020/9/18 22:06, Fam Zheng wrote: > > I can see how blocking in a slow io_submit can cause trouble for main > thread. I think one way to fix it (until it's made truly async in new > kernels) is moving the io_submit call to thread pool, and wrapped in a > coroutine, perhaps. >
I'm not sure if any other operation will block the main thread, other than io_submit(). > I'm not sure qmp timeout is a complete solution because we would still > suffer from a blocked state for a period, in this exact situation before > the timeout. Anyway, the qmp timeout may be the last measure to prevent the VM soft lockup. Ideally, after your fix of io_submit, this mechanism will never be triggered. Thanks, Zhenyu
