Re: [PATCH v2 2/2] xen/rwlock: add check_lock() handling to rwlocks

[Julien Grall <julien@xxxxxxx>]

Hi Jan,

On 03/11/2020 10:04, Jan Beulich wrote:
> On 03.11.2020 10:22, Jürgen Groß wrote:
> > On 03.11.20 10:02, Jan Beulich wrote:
> > > On 02.11.2020 14:12, Juergen Gross wrote:
> Question therefore is how much we care about keeping code
> ready for "real" preemption, when we have ample other places
> that would need changing first, before such could be enabled
The question we should ask ourself is whether we think one would want to 
use preemption in Xen.
Some of the emulation in Xen on Arm (e.g. ITS, SMMUv3, set/way) would 
have been easier to implement if the code were preemptible.
I also hear time to time stakeholders asking for preemptible spin lock 
(this is useful for RT).
Therefore, I think there are values to keep the code as much as possible 
preempt-ready.
Cheers,

--
Julien Grall