Re: [Xen-devel] [PATCH v2 02/45] ARM: Implement vcpu_kick()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 21.03.18 at 05:10, <julien.grall@xxxxxxx> wrote:
> On 03/20/2018 10:35 AM, Jan Beulich wrote:
>>>>> On 15.03.18 at 21:30, <andre.przywara@xxxxxxxxxx> wrote:
>>> If we change something in a vCPU that affects its runnability or
>>> otherwise needs the vCPU's attention, we might need to tell the scheduler
>>> about it.
>>> We are using this in one place (vIRQ injection) at the moment, but will
>>> need this at more places soon.
>>> So let's factor out this functionality, using the already existing
>>> vcpu_kick() prototype (used in x86 only so far), to make this available
>>> to the rest of the Xen code.
>> 
>> Having just seen this among the commits having gone in recently -
>> was it considered to make this a common function? The
>> implementations currently differ, but I'm not sure I see why that
>> needs to be. With x86's vcpu_kick_softirq() handler doing nothing
>> I could see the ARM implementation be suitable for x86, just like
>> I could see the x86 implementation be suitable for ARM.
> I considered it when reviewing the patch but discard it I wasn't 
> entirely sure if it was possible to make it common and  I wanted this 
> series to move forward (it is 50 patches series)!
> 
> I would be happy to consider any patch to make them common. My 
> preference would tend to go towards the Arm solution as it has a 
> slightly smaller overhead to kick a vCPU. Indeed the x86 version 
> requires to raise a softirq and then send an IPI to the other CPU.

Yes, that's my preference too. I'll send something after 4.11 has
settled.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel