Re: [Xen-devel] [PATCH 1/3] xen/sched: populate cpupool0 only after all cpus are up

[Juergen Gross <jgross@xxxxxxxx>]

On 13.08.19 18:07, Dario Faggioli wrote:
> On Fri, 2019-08-02 at 15:07 +0200, Juergen Gross wrote:
> > With core or socket scheduling we need to know the number of siblings
> > per scheduling unit before we can setup the scheduler properly. In
> > order to prepare that do cpupool0 population only after all cpus are
> > up.
> >
> > With that in place there is no need to create cpupool0 earlier, so
> > do that just before assigning the cpus. Initialize free cpus with all
> > online cpus at that time in order to be able to add the cpu notifier
> > late, too.
> So, now that this series has been made independent, I think that
> mentions to the core-scheduling one should be dropped.
>
> I mean, it is at least possible that this series would go in, while the
> core-scheduling one never will. And at that point, it would be very
> hard, for someone doing archaeology, to understand what went on.
>
> It seems to me that, this patch, simplifies cpupool initialization (as,
> e.g., the direct call to the CPU_ONLINE notifier for the BSP was IMO
> rather convoluted). And that is made possible by moving the
> initialization itself to a later point, making all the online CPUs look
> like free CPUs, and using the standard (internal) API directly (i.e.,
> cpupool_assign_cpu_locked()) to add them to Pool-0.
>
> So, I'd kill the very first sentence and rearrange the rest to include
> at least a quick mention to the simplification that we achieve.
Fine with me.


Juergen


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