perf/x86: Add constraint for IVB CYCLE_ACTIVITY:CYCLES_LDM_PENDING
The IvyBridge event CYCLE_ACTIVITY:CYCLES_LDM_PENDING can only be measured on counters 0-3 when HT is off. When HT is on, you only have counters 0-3. If you program it on the eight counters for 1s on a 3GHz IVB laptop running a noploop, you see: 2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING 3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING Clearly the last 4 values are bogus. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: zheng.z.yan@intel.com Cc: dhsharp@google.com Link: http://lkml.kernel.org/r/20130911152222.GA28761@google.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
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