From 03de874aa76ac0adcf6f56ebf3de623d09a5dde3 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 7 Aug 2014 17:08:54 -0700 Subject: [PATCH] perf/x86: Fix :pp without LBR 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 Signed-off-by: Peter Zijlstra Cc: kan.liang@intel.com Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/1407456534-15747-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 2879ecdaac43..0646d3b63b9d 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -387,7 +387,7 @@ int x86_pmu_hw_config(struct perf_event *event) precise++; /* Support for IP fixup */ - if (x86_pmu.lbr_nr) + if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2) precise++; } -- 2.20.1