767a65e9f3
Given max_worker is 1, and we currently have 1 running and it is
exiting. There may be race like:
io_wqe_enqueue worker1
no work there and timeout
unlock(wqe->lock)
->insert work
-->io_worker_exit
lock(wqe->lock)
->if(!nr_workers) //it's still 1
unlock(wqe->lock)
goto run_cancel
lock(wqe->lock)
nr_workers--
->dec_running
->worker creation fails
unlock(wqe->lock)
We enqueued one work but there is no workers, causes hung.
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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.