This fixes a side effect of Kan's earlier patch to probe the LBRs at boot
time. Normally when the LBRs are disabled cycles:pp is disabled too.
So for example cycles:pp doesn't work.
However this is not needed with PEBSv2 and later (Haswell) because
it does not need LBRs to correct the IP-off-by-one.
So add an extra check for PEBSv2 that also allows :pp
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: kan.liang@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/1407456534-15747-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
precise++;
/* Support for IP fixup */
- if (x86_pmu.lbr_nr)
+ if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
precise++;
}