[PATCH 0/6] powerpc: SMT priority (PPR) save and restore

Haren Myneni haren at linux.vnet.ibm.com
Fri Dec 7 18:44:23 EST 2012


This patch-set is created against your tree (next branch) and fixed the build failure that you pointed. 

Changes from the previous version:
- Changes for PPR save/restore in denorm_exception_hv, data_access_slb_relon_pSeries and instruction_access_slb_relon_pSeries 
  exception vectors (P8) code.
- Fix build failure with ppc64e_defconfig
- Macro name changes (HMT_MEDIUM_PPR_DISCARD and HMT_MEDIUM_PPR_SAVE) and other fixes as Michael Neuling suggested

[PATCH 0/6] powerpc: SMT priority (PPR) save and restore

On P7/P8 systems, users can define SMT priority levels 2,3 and 4 for
processes so that some can run higher priority than the other ones.
In the current kernel, the default priority is set to 4 which prohibits
processes for using higher priority. Also the kernel boosts the priority to
4 during exceptions without saving the user defined priorities when
the task enters the kernel. So we will be loosing the process PPR value
and can not be restored it back when the task exits the kernel.

This patch-set implements saving and restore the user defined PPR value
for all tasks.

With null_syscall testcase (http://ozlabs.org/~anton/junkcode/null_syscall.c),
this feature takes around extra 10 CPU cycles on average for 25 samples.
Haren Myneni (6):
  powerpc: Move branch instruction from ACCOUNT_CPU_USER_ENTRY to caller
  powerpc: Enable PPR save/restore
  powerpc: Increase exceptions arrays in paca struct to save PPR
  powerpc: Define ppr in thread_struct
  powerpc: Macros for saving/restore PPR
  powerpc: Implement PPR save/restore

 arch/powerpc/include/asm/cputable.h      |    7 +++-
 arch/powerpc/include/asm/exception-64s.h |   59 +++++++++++++++++++++++++-----
 arch/powerpc/include/asm/paca.h          |    6 ++--
 arch/powerpc/include/asm/ppc_asm.h       |   27 +++++++++++++-
 arch/powerpc/include/asm/processor.h     |   12 ++++++
 arch/powerpc/include/asm/reg.h           |    1 +
 arch/powerpc/kernel/asm-offsets.c        |    1 +
 arch/powerpc/kernel/entry_64.S           |    6 +++-
 arch/powerpc/kernel/exceptions-64e.S     |    3 +-
 arch/powerpc/kernel/exceptions-64s.S     |   23 +++++++-----
 arch/powerpc/kernel/process.c            |    2 +
 11 files changed, 119 insertions(+), 28 deletions(-)

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