• Vaidyanathan Srinivasan's avatar
    powerpc: Add support for new hcall H_BEST_ENERGY · 5742bd85
    Vaidyanathan Srinivasan authored
    Create sysfs interface to export data from H_BEST_ENERGY hcall
    that can be used by administrative tools on supported pseries
    platforms for energy management	optimizations.
    
    sys/device/system/cpu/pseries_(de)activate_hint_list and
    sys/device/system/cpu/cpuN/pseries_(de)activate_hint will provide
    hints for activation and deactivation of cpus respectively.
    
    These hints are abstract number given by the hypervisor based
    on the extended knowledge the hypervisor has regarding the
    system topology and resource mappings.
    
    The activate and the deactivate sysfs entry is for the two
    distinct operations that we could do for energy savings.  When
    we have more capacity than required, we could deactivate few
    core to save energy.  The choice of the core to deactivate
    will be based on /sys/devices/system/cpu/deactivate_hint_list.
    The comma separated list of cpus (cores) will be the preferred
    choice.  If we have to activate some of the deactivated cores,
    then /sys/devices/system/cpu/activate_hint_list will be used.
    
    The per-cpu file
    /sys/device/system/cpu/cpuN/pseries_(de)activate_hint further
    provide more fine grain information by exporting the value of
    the hint itself.
    
    Added new driver module
    	arch/powerpc/platforms/pseries/pseries_energy.c
    under new config option CONFIG_PSERIES_ENERGY
    Signed-off-by: default avatarVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    5742bd85
Kconfig 3.02 KB