[dm-devel] [PATCH] dm-mpath: Requeue after a small delay if blk_get_request() fails

[Bart Van Assche]

On Fri, 2017-04-07 at 16:50 -0700, Bart Van Assche wrote:
> If blk_get_request() returns ENODEV then multipath_clone_and_map()
> causes a request to be requeued immediately. This can cause a
> kworker thread to spend 100% of the CPU time of a single core in
> __blk_mq_run_hw_queue() and also can cause device removal to
> never finish.
> 
> Avoid this by only requeuing after a delay if blk_get_request()
> fails. Additionally, reduce the requeue delay.

Hello Mike,

The v4.12 merge window will open soon. Have you already had the
time to review this patch?

Thanks,

Bart.