From dff5da6d09daaab40a8741dce0ed3c2e94079de2 Mon Sep 17 00:00:00 2001 From: Yong Wang Date: Fri, 12 Jun 2009 16:08:55 +0800 Subject: [PATCH] perf_counter/x86: Add a quirk for Atom processors The fixed-function performance counters do not work on current Atom processors. Use the general-purpose ones instead. Signed-off-by: Yong Wang Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: <20090612080855.GA2286@ywang-moblin2.bj.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_counter.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 895c82e..275bc14 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -968,6 +968,13 @@ fixed_mode_idx(struct perf_counter *counter, struct hw_perf_counter *hwc) if (!x86_pmu.num_counters_fixed) return -1; + /* + * Quirk, IA32_FIXED_CTRs do not work on current Atom processors: + */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86_model == 28) + return -1; + event = hwc->config & ARCH_PERFMON_EVENT_MASK; if (unlikely(event == x86_pmu.event_map(PERF_COUNT_HW_INSTRUCTIONS))) -- 2.7.4