Part of the energy aware scheduler work is concerned by test and measurement tools such as idlestat[1]. This relies on the ability to trace wake-up events, mainly IRQs and IPIs.
While IRQs are already well instrumented with tracepoints, IPIs are rather lacking on that front, and completely invisible on ARM.
This series defines generic IPI tracepoints and adds them to ARM and ARM64. An attempt at adding them to X86 is also included for comments.
[1] https://wiki.linaro.org/WorkingGroups/PowerManagement/Resources/Tools/Idlest...
diffstat:
arch/arm/kernel/smp.c | 72 ++++++++++++++++++++------------ arch/arm64/kernel/smp.c | 67 +++++++++++++++++++----------- arch/x86/kernel/smp.c | 16 ++++++++ include/trace/events/ipi.h | 89 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 192 insertions(+), 52 deletions(-)