On Fri, 2013-04-05 at 13:22 -0500, Nathan Fontenot wrote:
> Agreed, having to call stop_machine() for each cpu that gets updated is
> pretty brutal. The plus side is that PRRN events should a rare occurrence
> and not cause too much pain.
So that doesn't happen on VPHN changes ?
> The current design ties into the of notification chain so that we can do
> the affinity update when the affinity property in the device tree is updated.
> Switching to doing one stop and updating all of the cpus would require a
> design change....and....
>
> I went back and looked at the code again and there is another issue with
> way this is done. Tying into the of notification chain is great for
> being informed of when a property changes but the code (from patch 6/11)
>
> + case OF_RECONFIG_ADD_PROPERTY:
> + case OF_RECONFIG_UPDATE_PROPERTY:
> + update = (struct of_prop_reconfig *)data;
> + if (!of_prop_cmp(update->dn->type, "cpu")) {
> + u32 core_id;
> + of_property_read_u32(update->dn, "reg", &core_id);
> + stage_topology_update(core_id);
> + rc = NOTIFY_OK;
> + }
> + break;
>
> Does not check to see which property is being updated and just assumes
> the affinity is being updated. This code as is will do an affinity update
> every time any property of a cpu is updated or added.
>
> Since this needs an update I will also look at possibly doing this so
> that we call stop_machine only once.
Any new patch set ?
Cheers,
Ben.
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