Re: [RFC] net/mlx5_core/en_main: Remove deprecated create_workqueue

From: Tejun Heo
Date: Fri Jul 29 2016 - 08:25:27 EST


Hello,

On Fri, Jul 29, 2016 at 01:30:05AM +0300, Saeed Mahameed wrote:
> > Are the workitems being used on a memory reclaim path?
>
> do you mean they need to allocate memory ?

It's a bit convoluted. A workqueue needs WQ_MEM_RECLAIM flag to be
guaranteed forward progress under memory pressure, so any workqueue
which may be depended upon during memory reclaim should have the flag
set; otherwise, the system can deadlock (try to reclaim memory, hits
the wq which can't make forward progress due to lack of memory). For
network devices, the requirement comes from block-over-network or nfs
which can be involved in memory reclaim.

Thanks.

--
tejun