On 8/4/19 1:10 PM, Mike Christie wrote: > This fixes a bug added in 4.10 with commit: > > commit 9561a7ade0c205bc2ee035a2ac880478dcc1a024 > Author: Josef Bacik <[email protected]> > Date: Tue Nov 22 14:04:40 2016 -0500 > > nbd: add multi-connection support > > that limited the number of devices to 256. Before the patch we could > create 1000s of devices, but the patch switched us from using our > own thread to using a work queue which has a default limit of 256 > active works. > > The problem is that our recv_work function sits in a loop until > disconnection but only handles IO for one connection. The work is > started when the connection is started/restarted, but if we end up > creating 257 or more connections, the queue_work call just queues > connection257+'s recv_work and that waits for connection 1 - 256's > recv_work to be disconnected and that work instance completing. > > Instead of reverting back to kthreads, this has us allocate a > workqueue_struct per device, so we can block in the work.
Applied for 5.4, thanks Mike. -- Jens Axboe
