Re: [PATCH 5.4] io_uring: prevent sq_thread from spinning when it should stop

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Feb 27, 2020 at 11:43:11AM +0100, Stefano Garzarella wrote:
> [ Upstream commit 7143b5ac5750f404ff3a594b34fdf3fc2f99f828 ]
> 
> This patch drops 'cur_mm' before calling cond_resched(), to prevent
> the sq_thread from spinning even when the user process is finished.
> 
> Before this patch, if the user process ended without closing the
> io_uring fd, the sq_thread continues to spin until the
> 'sq_thread_idle' timeout ends.
> 
> In the worst case where the 'sq_thread_idle' parameter is bigger than
> INT_MAX, the sq_thread will spin forever.
> 
> Fixes: 6c271ce2f1d5 ("io_uring: add submission polling")
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> Signed-off-by: Jens Axboe <axboe@kernel.dk>
> ---
>  fs/io_uring.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)

thanks for this, now queued up.

greg k-h