From 125580380f418000b1a06d9a54700f1191b6e561 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Thu, 10 Dec 2009 19:56:34 +0300 Subject: [PATCH] x86, perf events: Check if we have APIC enabled Ralf Hildebrandt reported this boot warning: | Running a vanilla 2.6.32 as Xen DomU, I'm getting: | | [ 0.000999] CPU: Physical Processor ID: 0 | [ 0.000999] CPU: Processor Core ID: 1 | [ 0.000999] Performance Events: AMD PMU driver. | [ 0.000999] ------------[ cut here ]------------ | [ 0.000999] WARNING: at arch/x86/kernel/apic/apic.c:249 native_apic_write_dummy So we need to check if APIC functionality is available, and not just in the P6 driver but elsewhere as well. Reported-by: Ralf Hildebrandt Signed-off-by: Cyrill Gorcunov Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <20091210165634.GF5086@lenovo> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 1342f236e32..18f05eccbb6 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -2066,12 +2066,6 @@ static __init int p6_pmu_init(void) x86_pmu = p6_pmu; - if (!cpu_has_apic) { - pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n"); - pr_info("no hardware sampling interrupt available.\n"); - x86_pmu.apic = 0; - } - return 0; } @@ -2163,6 +2157,16 @@ static __init int amd_pmu_init(void) return 0; } +static void __init pmu_check_apic(void) +{ + if (cpu_has_apic) + return; + + x86_pmu.apic = 0; + pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n"); + pr_info("no hardware sampling interrupt available.\n"); +} + void __init init_hw_perf_events(void) { int err; @@ -2184,6 +2188,8 @@ void __init init_hw_perf_events(void) return; } + pmu_check_apic(); + pr_cont("%s PMU driver.\n", x86_pmu.name); if (x86_pmu.num_events > X86_PMC_MAX_GENERIC) {