Re: [linuxwifi] x86/thermal: AB-BA dependency between mvm->mutex and tz->lock

From: Jiri Kosina
Date: Thu Aug 03 2017 - 09:09:39 EST


On Thu, 3 Aug 2017, Jiri Kosina wrote:

> > I see the workqueue allocation you mentioned. I'll try to move this
> > allocation out of the mutex and see how it goes.
>
> I have been briefly looking into this as well -- it'll basically have to
> be moved out of the trans_pcie->mutex context, but
>
> (a) I'm not sure whether that's actually safe
> (b) iwl_pcie_rx_reuse_rbd() (which is where corresponding work is being
> queued) is not a proper context either (it's atomic context)

Actually moving it out of trans_pcie->mutex is likely not to be enough,
the dependency would still be there, just the graph will have one vertex
less, with the dependency going directly from mvm mutex to
cpu_hotplug_lock.

--
Jiri Kosina
SUSE Labs