RFC hrtimer group events

This series is an attempt to link perf group events with a hrtimer, so that when the hrtimer fires all counters in the group are sampled. The reason this functionality is needed is because some performance counters cannot generate any form of interrupts, such as on SH or the power consumption counters on x86.

Peter, I'm sending this as an RFC because I'm not convinced I've got this patch series completely right. I've run it a few times on SH and the results seem sensible, e.g. monitoring L1-dcache-load-misses has flush_dcache_all() near the top of the list, but I just wanted to get this out so that people could review it early before I go any further.

One thing worth noting is that I've essentially hijacked group events so that they only work specifically for the hrtimer case. That's probably not right, in which case, we'll need some more flags to distinguish hrtimer-backed group from non-hrtimer-backed group.

Matt Fleming (5):
perf: Check if we should exclude idle thread in perf_exclude_event()
perf: Turn the group counter values into delta values
perf: Add hrtimer code for PMI-less hardware counters
sh: Add support for sampling counters
perf: Add support for PERF_SAMPLE_READ samples

 arch/sh/kernel/perf_event.c |    3 +-
 include/linux/perf_event.h  |    4 ++
 kernel/perf_event.c         |  111 +++++++++++++++++++++++++++++++++++++++++-
 tools/perf/builtin-record.c |   70 ++++++++++++++++++++++++---
 tools/perf/builtin-report.c |   19 +++++++-
 tools/perf/util/event.c     |    7 ++-
 tools/perf/util/event.h     |   15 ++++++
 7 files changed, 213 insertions(+), 16 deletions(-)