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| author | Yong Wang | 2009-05-29 07:28:35 +0200 |
|---|---|---|
| committer | Ingo Molnar | 2009-05-29 09:04:58 +0200 |
| commit | c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7 (patch) | |
| tree | 4e674688eb9ba7a84ab34db4bf51cfca34edf6ed /arch/x86/kernel/cpu/perf_counter.c | |
| parent | perf_counter tools: Fix top symbol table max_ip typo (diff) | |
| download | kernel-qcow2-linux-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.tar.gz kernel-qcow2-linux-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.tar.xz kernel-qcow2-linux-c323d95fa4dbe0b6bf6d59e24a0b7db067dd08a7.zip | |
perf_counter/x86: Always use NMI for performance-monitoring interrupt
Always use NMI for performance-monitoring interrupt as there could be
racy situations if we switch between irq and nmi mode frequently.
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
LKML-Reference: <20090529052835.GA13657@ywang-moblin2.bj.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/perf_counter.c')
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 2eeaa99add1c..316b0c995f38 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -604,7 +604,7 @@ try_generic: hwc->counter_base = x86_pmu.perfctr; } - perf_counters_lapic_init(hwc->nmi); + perf_counters_lapic_init(); x86_pmu.disable(hwc, idx); @@ -863,24 +863,15 @@ void set_perf_counter_pending(void) apic->send_IPI_self(LOCAL_PENDING_VECTOR); } -void perf_counters_lapic_init(int nmi) +void perf_counters_lapic_init(void) { - u32 apic_val; - if (!x86_pmu_initialized()) return; /* - * Enable the performance counter vector in the APIC LVT: + * Always use NMI for PMU */ - apic_val = apic_read(APIC_LVTERR); - - apic_write(APIC_LVTERR, apic_val | APIC_LVT_MASKED); - if (nmi) - apic_write(APIC_LVTPC, APIC_DM_NMI); - else - apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR); - apic_write(APIC_LVTERR, apic_val); + apic_write(APIC_LVTPC, APIC_DM_NMI); } static int __kprobes @@ -1054,7 +1045,7 @@ void __init init_hw_perf_counters(void) pr_info("... counter mask: %016Lx\n", perf_counter_mask); - perf_counters_lapic_init(0); + perf_counters_lapic_init(); register_die_notifier(&perf_counter_nmi_notifier); } |