Wall time clocks + change in access rules

My another attempt to get my patches reviewed. For
the convenience of a prospective reviewer I've written
a set of tests for this kernel change. One may get them using:

git clone http://pentium.hopto.org/~thinred/repos/clock-test.git

During our work we encountered a problem of obtaining
a reliable and fine-grained measurements of CPU time/wall time
of a process/thread. The existing methods (taskstats, procfs,
POSIX CPU clocks) have either unfriendly interface (taskstats)
or give unsatisfactory precision (procfs). However, even
the most precise and clean interface, POSIX CPU clocks,
is limited only to threads in the same thread group.

The following patches introduce three changes:
  * new per process/thread wall time clocks --
    CLOCK_PROCESS_WALLTIME_ID and CLOCK_THREAD_WALLTIME_ID;
    one can also access wall time of a process/thread
    using clocks constructed from macros in posix-timers.h
  * less restricted access to CPU and wall clocks --
    user can access them for all their threads
  * minor refactoring/renaming to reflect the changes.

Tomasz Buchert (4):
  posix-timers: Refactoring of CPUCLOCK* macros
  posix-cpu-timers: Introduction of wall clocks
  posix-cpu-timers: Wider access to the thread clocks
  posix-cpu-timers: posix-cpu-timers.c renamed to posix-task-timers.c

 include/linux/posix-timers.h |   52 +-
 include/linux/sched.h        |    2 +-
 include/linux/time.h         |    2 +
 kernel/Makefile              |    2 +-
 kernel/itimer.c              |   14 +-
 kernel/posix-cpu-timers.c    | 1642 -------------------------------------
 kernel/posix-task-timers.c   | 1852 ++++++++++++++++++++++++++++++++++++++++++
 kernel/posix-timers.c        |   25 +-
 8 files changed, 1924 insertions(+), 1667 deletions(-)
 delete mode 100644 kernel/posix-cpu-timers.c
 create mode 100644 kernel/posix-task-timers.c