Messages in this thread | | | Date | Sun, 27 May 2018 22:07:08 +0200 | From | Borislav Petkov <> | Subject | Re: smpboot seems to be confused on dual EPYC system |
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On Sun, May 20, 2018 at 03:23:32PM +0200, Gabriel C wrote: > Hello, > > I have an H11DSi-NT board with 2 * EPYC 7281 16C/32T CPUs. > > On that box for some reason spmboot things '4' logical packages > are possible.
First of all, which kernel?
> Max CPUs can be 128 ( 2 * 32C/64T ), however only 2 CPUs are possible > not 4 and therefor there is no way to add other 64 hotplug CPUs. > ( not even sure cpu hotplug will work here ) > > $ dmesg | egrep "smpboot|NR_CPUS|CPUs" > [ 0.000000] smpboot: Allowing 128 CPUs, 64 hotplug CPUs
Your BIOS is made to support 32-Core CPUs too.
> [ 0.000000] setup_percpu: NR_CPUS:8192 nr_cpumask_bits:128 > nr_cpu_ids:128 nr_node_ids:8 > [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=128, Nodes=8 > [ 0.000000] RCU restricting CPUs from NR_CPUS=8192 to nr_cpu_ids=128. > [ 0.037000] smpboot: CPU0: AMD EPYC 7281 16-Core Processor (family: > 0x17, model: 0x1, stepping: 0x2)
That says 2 * 16C * 2T = 64T.
> [ 0.048005] smp: Bringing up secondary CPUs ... > [ 0.055042] .... node #0, CPUs: #1 #2 #3 > [ 0.079029] .... node #1, CPUs: #4 #5 #6 #7 > [ 0.111049] .... node #2, CPUs: #8 #9 #10 #11 > [ 0.143050] .... node #3, CPUs: #12 #13 #14 #15 > [ 0.175031] .... node #4, CPUs: #16 #17 #18 #19 > [ 0.217031] .... node #5, CPUs: #20 #21 #22 #23 > [ 0.249062] .... node #6, CPUs: #24 #25 #26 #27 > [ 0.281058] .... node #7, CPUs: #28 #29 #30 #31 > [ 0.313028] .... node #0, CPUs: #32 #33 #34 #35 > [ 0.345028] .... node #1, CPUs: #36 #37 #38 #39 > [ 0.377046] .... node #2, CPUs: #40 #41 #42 #43 > [ 0.409043] .... node #3, CPUs: #44 #45 #46 #47 > [ 0.441028] .... node #4, CPUs: #48 #49 #50 #51 > [ 0.473029] .... node #5, CPUs: #52 #53 #54 #55 > [ 0.505060] .... node #6, CPUs: #56 #57 #58 #59 > [ 0.537052] .... node #7, CPUs: #60 #61 #62 #63 > [ 0.562171] smp: Brought up 8 nodes, 64 CPUs > [ 0.562171] smpboot: Max logical packages: 4 > [ 0.562171] smpboot: Total of 64 processors activated (268089.53 BogoMIPS)
You have 64 logical CPUs.
So what is the problem?
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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