Messages in this thread | | | Date | Fri, 1 Feb 2019 22:57:59 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: Question on handling managed IRQs when hotplugging CPUs |
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On Fri, 1 Feb 2019, Hannes Reinecke wrote: > Thing is, if we have _managed_ CPU hotplug (ie if the hardware provides some > means of quiescing the CPU before hotplug) then the whole thing is trivial; > disable SQ and wait for all outstanding commands to complete. > Then trivially all requests are completed and the issue is resolved. > Even with todays infrastructure. > > And I'm not sure if we can handle surprise CPU hotplug at all, given all the > possible race conditions. > But then I might be wrong.
The kernel would completely fall apart when a CPU would vanish by surprise, i.e. uncontrolled by the kernel. Then the SCSI driver exploding would be the least of our problems.
Thanks,
tglx
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