Re: [PATCH] Avoid mask based num_possible_cpus and num_online_cpus -v5

[Tony Luck]

On Mon, Feb 13, 2012 at 12:44 PM, Srivatsa S. Bhat
<srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote:
> IOW, what output do you see from the following printk from
> arch/ia64/kernel/smpboot.c?
>
> printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
>         (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);

That is a complicated question - because linux-next also has patches
by Arjan that
change how (when) cpus are brought online. Initially I blamed his
patches and tried
reverting them ... and saw the symptom you are wondering about (message said
"Total of 1 processors", but the BogoMIPs was a number big enough to be all of
them. Thanks to you, I can now understand why.

Fix will be to stop ia64 from messing directly with cpu_online_map?

-Tony
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