linux_dsm_epyc7002/arch/powerpc/platforms/powernv/Kconfig
Michael Ellerman 40e275653e powerpc/powernv: Always enable SMP when building powernv
The powernv platform supports Power7 and later CPUs, all of which are
multithreaded and multicore.

As such we never build a SMP=n kernel for those machines, other than
possibly for debugging or running in a simulator.

In the debugging case we can get a similar effect by booting with
nr_cpus=1, or there's always the option of building a custom kernel with
SMP hacked out.

For running in simulators the code size reduction from building without
SMP is not particularly important, what matters is the number of
instructions executed. A quick test shows that a SMP=y kernel takes ~6%
more instructions to boot to a shell. Booting with nr_cpus=1 recovers
about half that deficit.

On the flip side, keeping the SMP=n kernel building can be a pain at
times. And although we've mostly kept it building in recent years, no
one is regularly testing that the SMP=n kernel actually boots and works
well on these machines.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-04-13 23:37:17 +10:00

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config PPC_POWERNV
depends on PPC64 && PPC_BOOK3S
bool "IBM PowerNV (Non-Virtualized) platform support"
select PPC_NATIVE
select PPC_XICS
select PPC_ICP_NATIVE
select PPC_XIVE_NATIVE
select PPC_P7_NAP
select PCI
select PCI_MSI
select EPAPR_BOOT
select PPC_INDIRECT_PIO
select PPC_UDBG_16550
select PPC_SCOM
select ARCH_RANDOM
select CPU_FREQ
select CPU_FREQ_GOV_PERFORMANCE
select CPU_FREQ_GOV_POWERSAVE
select CPU_FREQ_GOV_USERSPACE
select CPU_FREQ_GOV_ONDEMAND
select CPU_FREQ_GOV_CONSERVATIVE
select PPC_DOORBELL
select MMU_NOTIFIER
select FORCE_SMP
default y
config OPAL_PRD
tristate 'OPAL PRD driver'
depends on PPC_POWERNV
help
This enables the opal-prd driver, a facility to run processor
recovery diagnostics on OpenPower machines