[RFC V1 0/6] Generic Entry/Exit support for ppc64

[Ankur Arora]

Ankur Arora <ankur.a.arora at oracle.com> writes:

> Mukesh Kumar Chaurasiya <mchauras at linux.ibm.com> writes:
>
>> This is a syscall only implementation of generic entry/exit framework
>> for framework for ppc. IRQ handling is not done in this RFC.
>>
>> This will break the ppc32 build as of now which will be fixed along with
>> IRQ handling.
>>
>> Below are the performance benchmarks from perf bench basic syscall.
>> This is for 1,00,00,000 getppid() calls
>>
>> | Metric     | Without Generic Framework | With Generic Framework |
>> | ---------- | ------------------------- | ---------------------- |
>> | Total time | 0.904 [sec]               | 0.856 [sec]            |
>> | usecs/op   | 0.090403                  | 0.085638               |
>> | ops/sec    | 1,10,61,579               | 1,16,77,086            |
>>
>> That's ~5% degradation as of now.
>
> Is the table header inverted? That reads like a ~5% improvement with the
> generic version.

Please ignore. Just noticed your update down thread.

>> Mukesh Kumar Chaurasiya (6):
>>   powerpc: rename arch_irq_disabled_regs
>>   powerpc: Prepare to build with genreic entry/exit framework
>>   powerpc: introduce arch_enter_from_user_mode
>>   powerpc: Add flag in paca for register restore state
>>   powerpc: Introduce syscall exit arch functions
>>   powerpc: Enable Generic Entry/Exit for syscalls.
>>
>>  arch/powerpc/Kconfig                    |   1 +
>>  arch/powerpc/include/asm/entry-common.h | 158 ++++++++++++++++++++++++
>>  arch/powerpc/include/asm/hw_irq.h       |   4 +-
>>  arch/powerpc/include/asm/interrupt.h    | 117 +++++++++++++++++-
>>  arch/powerpc/include/asm/paca.h         |   1 +
>>  arch/powerpc/include/asm/stacktrace.h   |   8 ++
>>  arch/powerpc/include/asm/syscall.h      |   5 +
>>  arch/powerpc/include/asm/thread_info.h  |   1 +
>>  arch/powerpc/kernel/interrupt.c         | 153 ++++++-----------------
>>  arch/powerpc/kernel/ptrace/ptrace.c     | 103 ---------------
>>  arch/powerpc/kernel/signal.c            |   8 ++
>>  arch/powerpc/kernel/syscall.c           | 117 +-----------------
>>  arch/powerpc/kernel/traps.c             |   2 +-
>>  arch/powerpc/kernel/watchdog.c          |   2 +-
>>  arch/powerpc/perf/core-book3s.c         |   2 +-
>>  15 files changed, 336 insertions(+), 346 deletions(-)
>>  create mode 100644 arch/powerpc/include/asm/entry-common.h


--
ankur