From 2c33645d366d13b969d936b68b9f4875b1fdddea Mon Sep 17 00:00:00 2001 From: "Palik, Imre" Date: Mon, 8 Jun 2015 14:46:49 +0200 Subject: [PATCH] perf/x86: Honor the architectural performance monitoring version Architectural performance monitoring, version 1, doesn't support fixed counters. Currently, even if a hypervisor advertises support for architectural performance monitoring version 1, perf may still try to use the fixed counters, as the constraints are set up based on the CPU model. This patch ensures that perf honors the architectural performance monitoring version returned by CPUID, and it only uses the fixed counters for version 2 and above. (Some of the ideas in this patch came from Peter Zijlstra.) Signed-off-by: Imre Palik Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Anthony Liguori Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1433767609-1039-1-git-send-email-imrep.amz@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index afdd7c08d0fc..2813ea0f142e 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -3324,13 +3324,13 @@ __init int intel_pmu_init(void) * counter, so do not extend mask to generic counters */ for_each_event_constraint(c, x86_pmu.event_constraints) { - if (c->cmask != FIXED_EVENT_FLAGS - || c->idxmsk64 == INTEL_PMC_MSK_FIXED_REF_CYCLES) { - continue; + if (c->cmask == FIXED_EVENT_FLAGS + && c->idxmsk64 != INTEL_PMC_MSK_FIXED_REF_CYCLES) { + c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1; } - - c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1; - c->weight += x86_pmu.num_counters; + c->idxmsk64 &= + ~(~0UL << (INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed)); + c->weight = hweight64(c->idxmsk64); } }