Messages in this thread |  | | | Date | Thu, 2 Jun 2005 17:45:14 -0600 (MDT) | | From | Zwane Mwaikambo <> | | Subject | Re: [patch 2/5] x86_64: CPU hotplug support. |
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On Thu, 2 Jun 2005, Ashok Raj wrote:
> > > + lock_ipi_call_lock(); > > > cpu_set(smp_processor_id(), cpu_online_map); > > > mb(); > > > + unlock_ipi_call_lock(); > > > > What's that? Is this another smp_call_function race workaround? I thought > > there was an additional patch to avoid the broadcast. > > The other patch avoids sending to offline cpu's, but we read cpu_online_map > and clear self bit in smp_call_function. If a cpu comes online, dont we > want this cpu to take part in smp_call_function?
The lock being held in smp_call_function whilst we access cpu_online_map should prevent another processor coming online within that operation shouldn't it? So There shouldn't be any processors coming online except for right after or before an smp_call_function.
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