Re: [GIT PULL] x86/boot changes for v3.13

From: Ingo Molnar
Date: Tue Nov 12 2013 - 06:37:26 EST



* Borislav Petkov <bp@xxxxxxxxx> wrote:

> On Tue, Nov 12, 2013 at 12:23:38PM +0100, Ingo Molnar wrote:
> > So I suspect what Yinghai tried to say if CPU0 and CPU1 are not on the
> > same node we do the printout incorrectly.
>
> I hope your translation is correct :) I'd still like to get a
> confirmation from him though.
>
> > Arguably this was a pre-existing condition, but would be nice to fix
> > it now that this code has emerged out of steady bitrot! :-)
> >
> > How difficult would it be in your opinion?
>
> Well, I did try a weird, non-existant configuration:
>
> kvm ... -smp 6 -numa node,nodeid=0,cpus=0\;2\;3 -numa node,nodeid=1,cpus=1\;4\;5
>
> and what I get is:
>
> [ 0.068574] x86: Booting SMP configuration:
> [ 0.069006] .... node #1, CPUs: #1
> [ 0.147005] .... node #0, CPUs: #2 #3 #4 #5
> [ 0.445273] x86: Booted up 2 nodes, 6 CPUs
>
> Before my cleanup and after removing the "fixing up alternatives"
> message which hid things, the output looked like:
>
> [ 0.069621] smpboot: Booting Node 1, Processors # 1 OK
> [ 0.146006] smpboot: Booting Node 0, Processors # 2 # 3 # 4 # 5 OK
> [ 0.448320] Brought up 6 CPUs
>
> The problem is not the indentation but that the current code slaps all
> cpus on the last node, in this case node 0, because announce_cpu gets
> the cores one by one.
>
> A possible fix would be to collect the topology and dump it *only*
> *after* the last core has been announced.

Hm, I think it's actually a bonus that we see the individual CPUs printed
as they boot up. That way if there's a hang, the place where it hangs is
apparent, etc.

Thanks,

Ingo
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