Messages in this thread | | | Subject | Re: [PATCH 1/5] x86/smpboot: Add the missing description of possible_cpus | From | Dou Liyang <> | Date | Wed, 21 Mar 2018 17:34:12 +0800 |
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Hi Peter,
At 03/21/2018 05:08 PM, Peter Zijlstra wrote: > On Wed, Mar 21, 2018 at 01:33:24PM +0800, Dou Liyang wrote: >> How about: >> >> possible_cpus= [s390,x86_64] Set the number of possible CPUs which >> are determined by the ACPI tables MADT or mptables by >> default. possible_cpus=n : n >= 1 enforces the possible >> number to be 'n'. >> While nr_cpus is also be set: nr_cpus=m, choice the >> minimum one for the number of possible CPUs. > > So what is the exact difference between possible_cpus and nr_cpus ? I
the possible_cpus= can reset the number of possible CPUs, even bigger than 'num_processors + disabled_cpus', But nr_cpus= can't.
> konw maxcpus= limits the number of CPUs we bring up, and possible_cpus > limits the possible_map, but I'm not entirely sure what nr_cpus does > here. >
nr_cpus can limited the maximum CPUs that the kernel could support.
Here is a double check in case of using them at the same time, even if I think just using possible_cpus= is enough. :-)
Thanks, dou. > >
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