LTTng 0.52, scheduler instrumentation

LTTng 0.52, scheduler instrumentation

[Mathieu Desnoyers]

Hi,

I just released LTTng 0.52 for 2.6.27.4. It fixes the stuff I dreamt
about this morning. ;-)

Ingo what do you think about this first point ?

- I now only use 2 bytes to encode the task->state field in the trace.
  However it seems that 1 byte would be enough (bitmask of values 0 to
  127), except that -1 is used for "unrunnable". But when it's
  unrunnable, it should "never" be reach scheduler events, right ?

Changelog :
- Add kernel command line : force_tsc_sync=1 to force tsc
  synchronization at boot.
- Supports AMD64 X2 box with unsynchronized TSCs very well. Includes
  a warning that tells users to try
  force_tsc_sync=1 idle=poll and to disable PowerNow or Speedstep to get
  synchronized timestamp counters on x86. This workaround works very
  well.
- Default to no LTT alignment for traces if
  HAVE_EFFICIENT_UNALIGNED_ACCESS is selected.
- Fixed mixed up irq entry field names in (appeared in 0.51).

Some testing would be required with virtualization to see how it
behaves.

Mathieu

-- 
Mathieu Desnoyers
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