Messages in this thread | | | Date | Thu, 26 Jul 2012 16:41:15 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [RFC PATCH 0/6] CPU hotplug: Reverse invocation of notifiers during CPU hotplug |
| |
On 07/26/2012 04:32 PM, Thomas Gleixner wrote: > On Wed, 25 Jul 2012, Srivatsa S. Bhat wrote: >> On 07/25/2012 10:00 PM, Thomas Gleixner wrote: >>> While I thought about having a full dependency tracking system, I'm >>> quite convinced by now, that hotplug is a rather linear sequence which >>> does not provide much room for paralell setup/teardown. >>> >> >> Pretty much, when considering hotplug of a single CPU. >> >> (But when considering booting, Arjan had proposed (while discussing >> about his asynchronous booting patch) that it would be good to split >> up physical vs logical parts of the booting/hotplug, so that the >> physical part can happen in parallel with other CPUs, while the >> logical online can be done serially, much later. Anyway, this is >> slightly off-topic here, since we are mainly talking about hotplug >> of a single cpu here. I just thought of putting a word about that >> here, since we are discussing hotplug redesign anyways..) > > Well, the nice thing about having a proper state machine is that you > can tell the code to advance the BP only to the "kick the other cpu" > step, which is before the first sync point, so you can leave the state > there and continue with "bring it fully online" later. > > So that feature comes basically for free. :) >
Ah! Nice :-)
Regards, Srivatsa S. Bhat
| |