Re: [PATCH v2 4/8] evtchn: let evtchn_set_priority() acquire the per-channel lock

[Jan Beulich <jbeulich@xxxxxxxx>]

On 22.10.2020 13:17, Roger Pau Monné wrote:
> On Tue, Oct 20, 2020 at 04:09:41PM +0200, Jan Beulich wrote:
>> Some lock wants to be held to make sure the port doesn't change state,
>> but there's no point holding the per-domain event lock here. Switch to
>> using the finer grained per-channel lock instead.
> 
> While true that's a fine grained lock, it also disables interrupts,
> which the global event_lock didn't.

True, yet we're aiming at dropping this aspect again. Hence I've
added "(albeit as a downside for the time being this requires
disabling interrupts for a short period of time)".

>> FAOD this doesn't guarantee anything towards in particular
>> evtchn_fifo_set_pending(), as for interdomain channels that function
>> would be called with the remote side's per-channel lock held.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks.

Jan