From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> On PSeries LPARs, the data centers planners desire a more accurate view of system utilization per resource such as CPU to plan the system capacity requirements better. Such accuracy can be obtained by reading PURR/SPURR registers for CPU resource utilization.
Tools such as lparstat which are used to compute the utilization need to know [S]PURR ticks when the cpu was busy or idle. The [S]PURR counters are already exposed through sysfs. We already account for PURR ticks when we go to idle so that we can update the VPA area. This patchset extends support to account for SPURR ticks when idle, and expose both via per-cpu sysfs files. These patches are required for enhancement to the lparstat utility that compute the CPU utilization based on PURR and SPURR which can be found here : https://groups.google.com/forum/#!topic/powerpc-utils-devel/fYRo69xO9r4 Gautham R. Shenoy (3): powerpc/pseries: Account for SPURR ticks on idle CPUs powerpc/sysfs: Show idle_purr and idle_spurr for every CPU Documentation: Document sysfs interfaces purr, spurr, idle_purr, idle_spurr Documentation/ABI/testing/sysfs-devices-system-cpu | 39 ++++++++++++++++++++++ arch/powerpc/kernel/idle.c | 2 ++ arch/powerpc/kernel/sysfs.c | 32 ++++++++++++++++++ drivers/cpuidle/cpuidle-pseries.c | 28 ++++++++++------ 4 files changed, 90 insertions(+), 11 deletions(-) -- 1.9.4
