Messages in this thread | | | Date | Wed, 21 Mar 2018 10:41:21 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/5] x86/smpboot: Add the missing description of possible_cpus |
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On Wed, 21 Mar 2018, 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 > 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 limits the number of CPUs the kernel will handle. Think of it as a boot time override of NR_CPUs.
Way too many commandline switches though.
Thanks,
tglx
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