linux/debian/config/kernelarch-powerpc/config-arch-64-le

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##
## file: arch/powerpc/Kconfig
##
# CONFIG_CMDLINE_BOOL is not set
ppc64el: kernel: config: little-endian powerpc64 options This config has options for little-endian PowerPC64 systems. It shares most options with big-endian PowerPC64 systems. The differences are: - choice: Endianness selection Build a little endian kernel. - choice: Page size 64k pages have benefits (performance et al) over 4k pages on IBM POWER processors. The Debian ppc64el port primarily runs on this sort of hardware and chances are it will also run on hardware based on it (i.e., OpenPOWER) [1] [2]. - Maximum number of CPUs This was increased to 2048 (following pseries_le_defconfig). For the currently announced systems, the number of CPUs range between 80-192 (1 or 2 processor module(s) * 10 or 12 cores per module * 8 threads per core) [3]. This is enough to have to diverge from CONFIG_NR_CPUS=32 in the other powerpc ports. For future systems, it's likely larger ones will be announced. The rationale: consider the announced systems are classified as 'scale-out' and 'entry-level', plus larger ones have been historically made available for addressing other markets; and notice the largest POWER7 server has 1024 CPUs (threads) [4], and that the threads-per-core doubled from POWER7 to POWER8. So, the 2048 value is a reasonable 'max' in that projection. Certainly it is greater than what would be required for most systems, but I belive 'max' makes sense in that case, if we are not looking for kernel rebuild and/with different config for the larger systems (although I would be ok with flavours). - choice: Default CPUFreq governor As other architectures, we would prefer the default cpufreq governor to be 'ondemand'. The currently available cpufreq driver is for the PowerNV (non-virtualized) platform, where all processors are available. In that scenario, statically running at the highest frequency (specially on idle processors) is not very desireable for the hardware around (servers), and it is not unlikely for future hardware (possibly non-servers) to benefit too, considering that energy savings have been increasingly important on most environments. (Note: the powernv-cpufreq driver was introduced only in 3.15; so, this option has no effect in 3.14; it is harmless. I can put in patches for enabling this on 3.14 soon.) - Apple PowerMac based machines This is being disabled temporarily, until a patch makes upstream (restricting it to 'depends on !CPU_LITTLE_ENDIAN'). This hardware line has no (known) support for little endian mode currently, and disabling it has the useful effect of also disabling a lot of config options which 'depends on PPC_PMAC', thus saving tens of lines from changing config files. It indeed has to be disabled because it's enabled by default ('depends on BOOK3S', 'default y'), so even changing it from config files would not be sufficient. [1] 'OpenPOWER Foundation Unveils First Innovations and Roadmap' http://openpowerfoundation.org/press-releases/openpower-foundation-unveils-first-innovations-and-roadmap/ [2] 'POWER8 Reference Board now available for Development!' http://openpowerfoundation.org/technical/related-links/ [3] 'IBM Power System S812L and S822L' http://www-03.ibm.com/systems/power/hardware/s812l-s822l/specs.html [4] 'IBM Power 795 server' http://www-03.ibm.com/systems/power/hardware/795/perfdata.html Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> svn path=/dists/sid/linux/; revision=21422
2014-06-12 20:01:13 +00:00
##
## file: arch/powerpc/platforms/Kconfig.cputype
##
## choice: Endianness selection
# CONFIG_CPU_BIG_ENDIAN is not set
CONFIG_CPU_LITTLE_ENDIAN=y
## end choice
##
## file: arch/powerpc/platforms/powermac/Kconfig
##
#. This needs to be explicitly disabled currently (3.15)
# CONFIG_PPC_PMAC is not set
##
## file: drivers/cpufreq/Kconfig
##
## choice: Default CPUFreq governor
# CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
## end choice
##
## file: drivers/pcmcia/Kconfig
##
# CONFIG_PCMCIA is not set
##
## file: kernel/power/Kconfig
##
#. See #789070
# CONFIG_HIBERNATION is not set